MR556 A4 5.56 11" 10+1 BLK Manufacturer Model Number: 81001051 Manufacturer: Heckler and Koch (HK USA) Model: MR556 A4 Caliber: 223 Rem | 5.56 NATO Type: Semi-Auto Pistol Item Type: Firearm Firearm / Accessory Action: Semi-Auto Firearm / Accessory Capacity: 10 + 1 Finish: Black Sights: No Sights Stock Frame Grips: Collapsible / Folding Stock HK Endanced Ergonomic Grip Magazine Quantity and Description: 1 10 rd. Overall Length: 26.5" Weight: 6.61 lbs. Shipping Weight: 0.0 Feature: Short Stroke Gas Piston Feature: HK416 Upper Receiver Feature: M-LOK Handguard Optic Adjustable Objective: false Optic Reticle Illuminated: false