What's in the Box Diamondback DB15 300 Blackout Rifle Magpul Gen M3 PMAG Owner's Manual The Diamondback DB15 features a 10" Chrome Moly Vanadium barrel with an A2 flash hider; pistol-length, Direct Impingement gas system; shot-peened, magnetic particle inspected Mil-Spec 8620 carrier; 9" M-LOK handguard; SB tactical SBA3 brace; Magpul MOE grip and aluminum receivers. Includes 30rd Magpul Gen3 PMAG. Firearm Features MOE Magpul Grip Magpul Gen M3 PMAG Firearm Specifications Manufacturer: Diamondback Model: DB15 Caliber: 300 Blackout Barrel Length: 10" Overall Length: (Length Collapsed / Length Extended) 26 in / 28.50 in Twist Rate: 1:8 RH Finish: Black Sights: None Grips/Stock: SB Tactical Brace Magazine Capacity: 30-Rounds