Manufacturer: IWI Model Number: GAP28 Caliber: 5.56 NATO Action: Semi-auto Operating System: Closed rotating bolt, Long stroke gas piston Magazine Type: MAGPUL PMAG GEN M3 with Window Magazine Capacity: 30 Round Barrel Material:Chrome lined, Cold hammer forged, CrMoV Barrel Length: 13″ Overall Length: 32.125″ Open, 24″ Folded Weight: 7 Lbs 14.8 oz Rifling: 1:7″ Twist, 6 RH Grooves (5.56 NATO) Top Rail Length: 18″ Handguard: Free Float M-LOK Handguard with slots at 3,6, and 9