The GEN-12 15-round Drum Magazine fits in all GEN-12 shotguns and is proprietary to the GEN-12. The GEN-12 drum magazine is field serviceability, easy to load, durable, and compact for its capacity. The GEN-12 doesn't care if it is low brass or high brass. So get your favorite wal-mart ammo for plinking and your home defense ammo for when it counts. RESTRICTIONS: Some States may restrict the ownership, purchase, or possesion of a magazine capacity greater than 10 rounds. If you purchase and your state has a legal restriction for magazine capacity then Genesis Arms reserves the right to cancel and retain the restocking fee. It is the responsibility of the purchaser to know how federal, state, and local laws impact individual owernship, possession or purchase of magazines with greater capacity than 10 rounds. NOTICE When loading, you can not push the shells straigth down like you can on a AR rifle magazine. It loads more like a pistol magazine, as you have to load under the rear tabs of the magazine. There is also a open window on the rear of the drum which exposes a assist wheel to aid in loading.