If you own the officially licensed Smith & Wesson M&P9 M2.0 .177 Caliber BB pistol, this spare magazine is the perfect accessory to keep the action going. The drop-free magazine holds a single 12 g non-threaded CO2 cartridge and 18 BBs, providing reliable, consistent shooting. The convenient follower hold-down tab cut into the BB channel makes loading BBs easier and more efficient. Whether you're practicing magazine change drills or simply want to extend your time at the range, this spare magazine is a must-have. It is specifically designed to fit the BB pistol SKU 2255004, ensuring compatibility and seamless performance.