Butler Creek Flip-Open Objective Lens Cover, Black Polymer, Size 13, 38.90mm

A Butler Creek flip-open objective lens cover in Size 13 (38.90mm) is essential lens protection for any hunter or shooter serious about keeping their optics ready in the field. These custom-fit covers slide onto your scope's objective bell with a friction mount that holds firm without tools or adjustment—no straps, no slots, no fuss. When the moment comes, a quick thumb-flip opens the cover silently and stays out of your way while you take the shot.

The design philosophy is straightforward: protect your glass until you don't need protection anymore. The semi-O-ring seal keeps dust and moisture sealed out in wet grass, rain, and snow, while the air-tight fit prevents the lens fogging that can ruin a stalk. The black polymer construction is lightweight—less than an ounce—so it doesn't add noticeable weight or bulk to your rifle. The silent spring hinges won't produce a sound that could alert game, and the ambidextrous opening works equally well for left or right-handed shooters. Butler Creek tested these covers to –40°F, so they'll function in genuine backcountry cold.

Size 13 fits objective bells measuring 38.90mm in diameter. If you're building a reliable scope protection system—whether for a long-range hunting rifle, a tactical setup at the range, or backup optics in your truck—this is the no-nonsense solution that has earned trust among serious shooters for decades.

Key Features

• Fast flip-open design for quick access when you need it
• Silent spring hinges won't spook game or announce your position
• Water-tight and air-tight custom friction fit—no straps or adjustment required
• Semi-O-ring seal keeps out dust, moisture, and debris
• Tested to –40°F for extreme cold-weather use
• Ambidextrous operation works for left and right-handed shooters
• Lightweight black polymer construction (under 1 ounce)

Specifications

Frequently Asked Questions

Will a Size 13 cover fit my scope?

Size 13 is designed for objective bells measuring 38.90mm in diameter. Check your scope's objective diameter against this specification to confirm fit. Butler Creek offers multiple sizes, so if 38.90mm isn't your objective, a different size may be available.

How does the mounting system work?

The cover uses a custom-fit friction mount that grips your scope's objective bell without tools, straps, or permanent attachment. The semi-O-ring creates a tight, secure hold that stays in place during recoil and handling.

Can I use this cover on a left-handed rifle?

Yes. The flip-open design is ambidextrous, so the thumb-flip works equally well for both right and left-handed shooters.

What happens in cold weather?

Butler Creek tested these covers to –40°F, so they remain fully functional in extreme backcountry cold without becoming brittle or losing their seal.