High capacity 50 round drum magazine in 5.56 caliber for all M4/AR-15 type rifles. If you own an AR-15 rifle or pistol, get one of these while you can. This high-quality 50 round drum mag is made in South Korea to Mil specs. That means they work. Locks up tight and feeds flawlessly in all AR-15 rifles. Manufactured in South Korea for the Korean Military. These 50 round drum AR magazines are a quality unmatched by other manufacturers. They're manufactured in South Korea for the Korean Military for use in their M16 rifles but work equally well in AR-15 rifles. Made to exceed NATO Specs.