Butler Creek Flip-Open Objective Lens Cover, Black Polymer, Size 21, 44.10mm

The Butler Creek Flip-Open Objective Lens Cover in Size 21 (44.10mm) is a rugged, purpose-built lens protector designed for hunters and shooters who demand gear that keeps up with unpredictable field conditions. This black polymer cover mounts directly to your scope and opens instantly with a thumb flick, so you're never fumbling with caps when the moment to shoot arrives. Whether you're glassing in fog, rain, or snow, it seals tight to shield your objective lens from the elements without slowing you down.

Built with a semi-O-ring design, the cover creates an air-tight, water-tight barrier that keeps dust and moisture away from your optics—critical when you're hunting in extreme weather or storing gear between seasons. The friction-fit mounting system holds the cover securely in place without tools, and the silent spring hinges won't produce the noise that spooks game at close range. At less than an ounce, it adds virtually no weight to your setup, and it's rated to perform reliably in temperatures down to –40°F.

The truly ambidextrous design works equally well for left- and right-handed shooters, and the flip-open mechanism lets you keep your eye on target and your hands on the gun. Size 21 fits 44.10mm objective lenses—verify your scope's objective diameter before ordering to ensure a proper custom fit. For serious hunters and precision shooters who won't leave their glass unprotected, this is straightforward, no-nonsense lens cover engineering.

Key Features

• Flip-open design opens instantly with thumb pressure
• Air-tight semi-O-ring seal keeps out dust and moisture
• Water-tight friction-fit mounting anchors to your scope
• Silent spring hinges won't disturb game
• Truly ambidextrous for left and right-handed shooters
• Weighs less than one ounce
• Rated for extreme cold down to –40°F
• Black polymer construction

Specifications

Frequently Asked Questions

Will this Butler Creek lens cover fit my scope?

Size 21 is designed for 44.10mm objective lenses. Check your scope's objective diameter against the size chart to confirm the correct fit; using the wrong size will result in a poor seal and unreliable protection.

Does the flip-open cover make noise when I open it?

No. The spring hinges are engineered to operate silently, so opening the cover won't spook game or alert targets at the moment of truth.

Can I use this cover in wet weather?

Yes. The semi-O-ring design creates a water-tight seal, and the friction-fit mount keeps the cover secure even in rain, snow, and spray. It's also air-tight, so it protects your lens from moisture and dust.

Is this cover ambidextrous?

Yes. The flip-open mechanism works equally well for left-handed and right-handed shooters, so it adapts to your grip without modification.