The Caldwell Mag Caps are designed to securely fit on top of 10, 20 and 30 Round Mil-Spec AR-15 Magazines to keep dust out and protect bullet tips. When not in use they easily slip on the bottom of the magazine so they arent misplaced. They are made of non-marring flexible rubber to seal the magazine and keeps dust out and protects bullet tips. The slip on the bottom of the magazine is for storage while not in use.
Determined at checkout.