The Butler Creek Flip-Open OBJ is a hinged protective cover designed for the objective lens of optical scopes, helping to keep the lens clean while hunting, during transport, and in storage.
The Butler Creek Flip-Open OBJ is a hinged protective cover designed for the objective lens of optical scopes, helping to keep the lens clean while hunting, during transport, and in storage. The quietly opening, spring-loaded lid moves quickly out of the way with a thumb press, and the wide range of sizes allows you to find a suitable cover for optics of various diameters and shapes. Suitable for use To protect the objective lens of an optical scope For hunting and target shooting When transporting and storing optics In dusty, rainy, or snowy environments When moving through forests and brush To protect the lens from scratches and dirt For optics with a round objective housing For optics with an oval objective housing, if the model fits For users who want a quickly opening objective cover To create a set with the Butler Creek EYE eyepiece cover Why choose the Butler Creek Flip-Open OBJ? Designed for the objective-side lens of optical scopes Spring-loaded Flip-Open opening mechanism Opens with one hand and a thumb press Quiet hinged construction Suitable for both right- and left-handed users Helps protect the lens from dust, moisture, and scratches Mounts directly onto the objective housing Friction mount usually requires no tools Semi-ring seal helps reduce dust and moisture reaching the lens Each cover weighs less than 30 g Available in round and oval sizes Size range approximately 25.4–69.2 mm The EYE eyepiece cover is available separately Technical specifications Manufacturer: Butler Creek Product series: Flip-Open Product type: optic objective cover Designation: OBJ Mounting location: optical scope objective housing Opening: spring-loaded hinged lid Opening method: thumb press Mounting method: friction fit onto the optic housing Material: synthetic material Color: black Weight: under 30 g Smallest nominal size: 25.4 mm Largest nominal size: 69.2 mm Compatibility: determined by the external diameter of the objective housing Sales unit: one objective cover in the selected size All Butler Creek Flip-Open OBJ sizes The size shown below refers to the approximate outside diameter of the objective housing at the installation point. The size number does not always indicate a strictly increasing order of diameters. OBJ 01 – model 30010: 25.4 mm or 1.000" OBJ 02 – model 30020: 31.0 mm or 1.221" OBJ 02A – model 30025: 30.0 mm or 1.181" OBJ 03A – model 30030: 33.0 mm or 1.300" OBJ 03 – model 30035: 34.0 mm or 1.340" OBJ 04 – model 30040: 27.8 mm or 1.095" OBJ 05 – model 30050: 35.2 mm or 1.387" OBJ 07 – model 30070: 36.3 mm or 1.429" OBJ 09 – model 30090: 37.7 mm or 1.485" OBJ 10 – model 30100: 38.1 mm or 1.500" OBJ 11 – model 30110: oval, 39.1 × 34.0 mm or 1.54 × 1.34" OBJ 12 – model 30120: oval, 44.7 × 38.9 mm or 1.76 × 1.53" OBJ 13 – model 30130: 38.9 mm or 1.530" OBJ 15 – model 30150: 39.6 mm or 1.558" OBJ 17 – model 30170: 40.9 mm or 1.612" OBJ 19 – model 30190: 41.8 mm or 1.646" OBJ 20 – model 30200: 43.2 mm or 1.700" OBJ 21 – model 30210: 44.1 mm or 1.735" OBJ 23 – model 30230: 44.7 mm or 1.760" OBJ 25 – model 30250: 45.7 mm or 1.800" OBJ 26 – model 30260: 46.2 mm or 1.820" OBJ 27 – model 30270: 46.7 mm or 1.840" OBJ 28 – model 30280: 48.0 mm or 1.890" OBJ 29 – model 30290: 48.7 mm or 1.919" OBJ 30 – model 30300: 49.8 mm or 1.960" OBJ 31 – model 30310: 50.7 mm or 1.998" OBJ 33 – model 30330: 51.9 mm or 2.043" OBJ 34 – model 30340: 53.3 mm or 2.100" OBJ 39 – model 30390: 56.4 mm or 2.220" OBJ 40 – model 30400: 57.2 mm or 2.250" OBJ 43 – model 30430: 58.7 mm or 2.310" OBJ 44 – model 30440: 59.9 mm or 2.360" OBJ 45 – model 30450: 61.2 mm or 2.410" OBJ 46 – model 30460: 61.7 mm or 2.430" OBJ 47 – model 30470: 62.5 mm or 2.461" OBJ 48 – model 30480: 63.5 mm or 2.500" OBJ 51 – model 30510: 65.4 mm or 2.575" OBJ 53 – model 30535: 66.0 mm or 2.600" OBJ 53A – model 30530: 67.1 mm or 2.640" OBJ 54 – model 30540: 69.2 mm or 2.725" Dimensions are nominal values. The optic's surface coating, objective housing shape, and measuring point may affect actual fit, so be sure to measure the housing precisely before ordering. Included in the package One Butler Creek Flip-Open OBJ objective cover in the selected size The EYE eyepiece cover is not included and must be selected separately if needed. Frequently Asked Questions How to choose the correct size Butler Creek OBJ optic cover? Use a caliper to precisely measure the outer diameter of the optic's objective housing at the point where the cover will be installed. Compare your measurement to the OBJ size list. Do not rely solely on the nominal objective lens size marked on the optic. Will a 50 mm cover fit optics with a 50 mm objective? Not necessarily. The 50 mm marking typically indicates the lens's nominal diameter, but the outer diameter of the objective housing is larger. The correct Butler Creek OBJ size must be chosen according to the actual outside diameter of the housing. What if the measurement falls between two sizes? If possible, try the cover on the optic. The friction fit should be secure, but the cover should not be forced on. A cover that is too large may shift, while one that is too small may be damaged or put excess strain on the optic housing. Can the OBJ cover also be used on the eyepiece? Generally, no. OBJ models are designed for the objective (front) end of the optic. To protect the eyepiece, choose a suitable Butler Creek Flip-Open EYE cover. Are both optic covers included in the package? No. The sales unit includes one OBJ objective cover in the selected size. The EYE eyepiece cover is sold separately, as the two ends of the optic may require different sizes. Are oval-shaped covers available? Yes. OBJ 11 measures approximately 39.1 × 34.0 mm and OBJ 12 measures approximately 44.7 × 38.9 mm. For an oval objective housing, measure both its width and height separately. Does the cover make the optical scope waterproof? No. The cover and its semi-ring seal help keep dust and moisture away from the lens, but do not make the optic waterproof or replace proper drying and maintenance of the optic. When is the Butler Creek Flip-Open OBJ the right choice? The Butler Creek Flip-Open OBJ is suitable if you want a permanently installed protective cover on the objective lens of your optical scope that can be opened quickly and quietly when needed. This is practical for hunting, where the lens may be exposed to rain, snow, dust, branches, or other debris. If you want to protect both the eyepiece and objective with a single removable cover, a universal optic cover with a connecting strap may be more suitable. For housings that fall outside the size chart or are irregularly shaped, consider an elastic universal model. We recommend We recommend measuring the objective housing with a precise caliper and taking the measurement at the actual installation point. The 40, 44, 50, or 56 mm marking on the optic usually refers to the lens's nominal diameter, not the housing's outer diameter. For example, a 50 mm optic may require a significantly larger OBJ cover depending on the model. For round housings, check the diameter in at least two directions. If the measurements differ, the housing may be oval or asymmetrical. For an oval housing, choose OBJ 11 or OBJ 12 only if both the width and height match the cover dimensions. Install the cover on a clean, dry surface and ensure that the open lid does not touch the barrel, scope, suppressor, or other accessories. The cover should fit securely, but do not stretch it forcefully. For complete lens protection, add a suitable Butler Creek EYE cover to the eyepiece end of the optic. Quick-opening protection for your optic's objective lens The Butler Creek Flip-Open OBJ helps keep the front lens of your optical scope clean and ready to use in the field, at the range, or during transport. The wide selection of round and oval sizes allows you to find a cover for optics with various constructions, and a matching EYE cover provides additional protection at the eyepiece end.
The Butler Creek Flip-Open OBJ is a hinged protective cover designed for the objective lens of optical scopes, helping to keep the lens clean while hunting, during transport, and in storage. The quietly opening, spring-loaded lid moves quickly out of the way with a thumb press, and the wide range of sizes allows you to find a suitable cover for optics of various diameters and shapes. Suitable for use To protect the objective lens of an optical scope For hunting and target shooting When transporting and storing optics In dusty, rainy, or snowy environments When moving through forests and brush To protect the lens from scratches and dirt For optics with a round objective housing For optics with an oval objective housing, if the model fits For users who want a quickly opening objective cover To create a set with the Butler Creek EYE eyepiece cover Why choose the Butler Creek Flip-Open OBJ? Designed for the objective-side lens of optical scopes Spring-loaded Flip-Open opening mechanism Opens with one hand and a thumb press Quiet hinged construction Suitable for both right- and left-handed users Helps protect the lens from dust, moisture, and scratches Mounts directly onto the objective housing Friction mount usually requires no tools Semi-ring seal helps reduce dust and moisture reaching the lens Each cover weighs less than 30 g Available in round and oval sizes Size range approximately 25.4–69.2 mm The EYE eyepiece cover is available separately Technical specifications Manufacturer: Butler Creek Product series: Flip-Open Product type: optic objective cover Designation: OBJ Mounting location: optical scope objective housing Opening: spring-loaded hinged lid Opening method: thumb press Mounting method: friction fit onto the optic housing Material: synthetic material Color: black Weight: under 30 g Smallest nominal size: 25.4 mm Largest nominal size: 69.2 mm Compatibility: determined by the external diameter of the objective housing Sales unit: one objective cover in the selected size All Butler Creek Flip-Open OBJ sizes The size shown below refers to the approximate outside diameter of the objective housing at the installation point. The size number does not always indicate a strictly increasing order of diameters. OBJ 01 – model 30010: 25.4 mm or 1.000" OBJ 02 – model 30020: 31.0 mm or 1.221" OBJ 02A – model 30025: 30.0 mm or 1.181" OBJ 03A – model 30030: 33.0 mm or 1.300" OBJ 03 – model 30035: 34.0 mm or 1.340" OBJ 04 – model 30040: 27.8 mm or 1.095" OBJ 05 – model 30050: 35.2 mm or 1.387" OBJ 07 – model 30070: 36.3 mm or 1.429" OBJ 09 – model 30090: 37.7 mm or 1.485" OBJ 10 – model 30100: 38.1 mm or 1.500" OBJ 11 – model 30110: oval, 39.1 × 34.0 mm or 1.54 × 1.34" OBJ 12 – model 30120: oval, 44.7 × 38.9 mm or 1.76 × 1.53" OBJ 13 – model 30130: 38.9 mm or 1.530" OBJ 15 – model 30150: 39.6 mm or 1.558" OBJ 17 – model 30170: 40.9 mm or 1.612" OBJ 19 – model 30190: 41.8 mm or 1.646" OBJ 20 – model 30200: 43.2 mm or 1.700" OBJ 21 – model 30210: 44.1 mm or 1.735" OBJ 23 – model 30230: 44.7 mm or 1.760" OBJ 25 – model 30250: 45.7 mm or 1.800" OBJ 26 – model 30260: 46.2 mm or 1.820" OBJ 27 – model 30270: 46.7 mm or 1.840" OBJ 28 – model 30280: 48.0 mm or 1.890" OBJ 29 – model 30290: 48.7 mm or 1.919" OBJ 30 – model 30300: 49.8 mm or 1.960" OBJ 31 – model 30310: 50.7 mm or 1.998" OBJ 33 – model 30330: 51.9 mm or 2.043" OBJ 34 – model 30340: 53.3 mm or 2.100" OBJ 39 – model 30390: 56.4 mm or 2.220" OBJ 40 – model 30400: 57.2 mm or 2.250" OBJ 43 – model 30430: 58.7 mm or 2.310" OBJ 44 – model 30440: 59.9 mm or 2.360" OBJ 45 – model 30450: 61.2 mm or 2.410" OBJ 46 – model 30460: 61.7 mm or 2.430" OBJ 47 – model 30470: 62.5 mm or 2.461" OBJ 48 – model 30480: 63.5 mm or 2.500" OBJ 51 – model 30510: 65.4 mm or 2.575" OBJ 53 – model 30535: 66.0 mm or 2.600" OBJ 53A – model 30530: 67.1 mm or 2.640" OBJ 54 – model 30540: 69.2 mm or 2.725" Dimensions are nominal values. The optic's surface coating, objective housing shape, and measuring point may affect actual fit, so be sure to measure the housing precisely before ordering. Included in the package One Butler Creek Flip-Open OBJ objective cover in the selected size The EYE eyepiece cover is not included and must be selected separately if needed. Frequently Asked Questions How to choose the correct size Butler Creek OBJ optic cover? Use a caliper to precisely measure the outer diameter of the optic's objective housing at the point where the cover will be installed. Compare your measurement to the OBJ size list. Do not rely solely on the nominal objective lens size marked on the optic. Will a 50 mm cover fit optics with a 50 mm objective? Not necessarily. The 50 mm marking typically indicates the lens's nominal diameter, but the outer diameter of the objective housing is larger. The correct Butler Creek OBJ size must be chosen according to the actual outside diameter of the housing. What if the measurement falls between two sizes? If possible, try the cover on the optic. The friction fit should be secure, but the cover should not be forced on. A cover that is too large may shift, while one that is too small may be damaged or put excess strain on the optic housing. Can the OBJ cover also be used on the eyepiece? Generally, no. OBJ models are designed for the objective (front) end of the optic. To protect the eyepiece, choose a suitable Butler Creek Flip-Open EYE cover. Are both optic covers included in the package? No. The sales unit includes one OBJ objective cover in the selected size. The EYE eyepiece cover is sold separately, as the two ends of the optic may require different sizes. Are oval-shaped covers available? Yes. OBJ 11 measures approximately 39.1 × 34.0 mm and OBJ 12 measures approximately 44.7 × 38.9 mm. For an oval objective housing, measure both its width and height separately. Does the cover make the optical scope waterproof? No. The cover and its semi-ring seal help keep dust and moisture away from the lens, but do not make the optic waterproof or replace proper drying and maintenance of the optic. When is the Butler Creek Flip-Open OBJ the right choice? The Butler Creek Flip-Open OBJ is suitable if you want a permanently installed protective cover on the objective lens of your optical scope that can be opened quickly and quietly when needed. This is practical for hunting, where the lens may be exposed to rain, snow, dust, branches, or other debris. If you want to protect both the eyepiece and objective with a single removable cover, a universal optic cover with a connecting strap may be more suitable. For housings that fall outside the size chart or are irregularly shaped, consider an elastic universal model. We recommend We recommend measuring the objective housing with a precise caliper and taking the measurement at the actual installation point. The 40, 44, 50, or 56 mm marking on the optic usually refers to the lens's nominal diameter, not the housing's outer diameter. For example, a 50 mm optic may require a significantly larger OBJ cover depending on the model. For round housings, check the diameter in at least two directions. If the measurements differ, the housing may be oval or asymmetrical. For an oval housing, choose OBJ 11 or OBJ 12 only if both the width and height match the cover dimensions. Install the cover on a clean, dry surface and ensure that the open lid does not touch the barrel, scope, suppressor, or other accessories. The cover should fit securely, but do not stretch it forcefully. For complete lens protection, add a suitable Butler Creek EYE cover to the eyepiece end of the optic. Quick-opening protection for your optic's objective lens The Butler Creek Flip-Open OBJ helps keep the front lens of your optical scope clean and ready to use in the field, at the range, or during transport. The wide selection of round and oval sizes allows you to find a cover for optics with various constructions, and a matching EYE cover provides additional protection at the eyepiece end.
