Kydex Customs Sig P320/M17 Magazine CarrierOur Sig P320 M17 Magazine Carriers are designed to work with all Airsoft Sig Sauer P320 M17 and M18 on the market (Including the WE AEG F17 & F18). All of our Pistol Magazine Carriers use an MRD (Magazine Retention Device) which provides adjustable retention to the front of the magazine, allowing the carrier to hold on to the magazine with the perfect amount of resistance. To adjust the retention on the Magazine Carriers you need to screw or unscrew