Smith & Wesson M&P 9 M2.0 CO2 BB Pistol .177 caliber Drop free 18-round BB magazine Blowback action Ambidextrous slide release Last round hold open Max. velocity up to 400 FPS Under-muzzle Picatinny accessory rail Textured grip and backstrap Includes 3 interchangeable backstraps Trigger blade safety and manual side safety Barrel length: 4" Overall length: 7.5" Weight: 1.45 lbs. Uses a single 12-gram CO2 cartridge