The Caldwell Mag Charger Rimfire AR-15 Magazine Loader is the fastest AR-15 22LR magazine loader on the market. The Magazine Loader is compatible with all popular AR-15 22LR magazines with load assist mag button (including Mossberg). Constructed from durable polycarbonate, the Mag Loader can handle daily use! The Mag Loader features an ammo hopper that automatically orients round for loading and also holds up to 100 rounds of your favorite 22LR ammo. This magazine loader will not work with CMMG or Sig Sauer magazines.NoteStep 1. Load 22LR ammo into the hopperStep 2. Insert 22LR AR mag into the loaderStep 3. Insert hopper cover and gently shake to orient the ammo correctlyStep 4. Tilt up the mag charger, slide the magazine follower down and the ammo will slide into the mag