The PMAG Minus 10 Round Limiter installs in 20 or 30 round GEN M3 PMAG bodies, reducing the magazine capacity by ten rounds. Designed for sporting and hunting applications, installation of the Limiter is simple, tool-less, and requires no permanent modification of the magazine body. NOTE: Will NOT make a banned magazine legal! This product is intended for TEMPORARY capacity reduction of PMAG AR/M4 GEN M3 magazines. This product does not constitute a permanent capacity reduction. The user is responsible for knowing applicable laws in any jurisdiction that restricts magazines based on capacity or regulates magazine capacity for hunting. Please check all laws and regulations of your state and locality to determine the legality of your host ammunition magazines.