This is the brass catcher of choice for the U. S. Marines. This handy catcher attaches to all flat top and carry handle AR's by wrapping the Velcro strap around the handguard. The mouth automatically lines up with the ejection port and the zipper on the bottom lets you empty the catcher without removing it. It's semi rigid frame makes it ideal for all shooters so you don't hit your fellow shooters with hot brass. With it's heavy duty zippered bag it is quick to empty and get back to practice. The mesh bag design allows gases to vent away from the shooter and easily view how much brass has been collected. Holds approx. 60 spent cases. Can be used on all AR-15 style rifles, M-16, AR-15 with .22 kits, AR-15 with 9mm kits, AR-10's and great for the range or varmint hunting.