Shoot Thru Rifle Scope Covers-When seconds count, don't miss the shot. Size CG FITS scopes with 40 mm lens - see details below. Shoot Thru Scope covers are made from optical grade polycarbonate lenses so the view through your scope is crystal clear. Shoot-Thru Scope Covers are designed to fit a variety of similar sized scopes. Inside the cover there is a 60 taper to center on the scope and promote a good seal. Best fit is obtained when the scope fills most of the cover. Made in America. Scope Covers are very easy to use, perfectly clear, interchangeable lenses and never interfere with the perfect shot.