The Butler Creek 30210 Flip-Open Objective Scope Cover for a 44.10mm objective, size 21 in black polymer, delivers unmatched protection and rapid access for hunters and shooters, combining a fast flip-open design that keeps your eye on the target with silent spring hinges that wont spook game. This water-tight, air-tight scope cover uses custom-fit friction mounts to securely anchor to your objective, ensuring a tight seal against dust and moisture and maintaining clear optics in extreme conditions. Tested to -40F, the ambidextrous, lightweight cover weighs less than an ounce, providing reliable performance without adding bulk to your setup. Engineered to fit precisely, the Size 21 cover integrates seamlessly with your scope, offering a truly versatile solution that opens with a thumb touch so you can take the shot within that narrow window of opportunity. Built by Butler Creek, this scope accessory blends durable construction with practical operation, delivering consistent protection and quick access whenever youre in the field.