Rainier Arms Rainier Industries Pro Series MK1 M-Lok AR-15 Handguard Black 15 in. To achieve this we designed it an extended aluminum barrel nut and larger stainless steel mounting lugs for better rigidity to maintain a mechanical zero. The Pro Series MLOK rail is built to stand up to the rigors and demands of what your duty weapon requires. Specifications for Rainier Arms Rainier Industries Pro Series MK1 M-Lok AR-15 Handguard: Manufacturer: Rainier Arms Color: Black Finish: Mil Spec Type III Hard Coat Anodized Fabric/Material: 6000 Series Aluminium Gun Make: AR Platform Gun Model: AR-15 Gun Rail: M-LOK Attachment Type: M-LOK Features of Rainier Arms Rainier Industries Pro Series MK1 M-Lok AR-15 Handguard CNC machined 6000 series extruded Aluminum Hard Coat Anodized Milspec Type III Class 2 Black Barrel Nut is 7075 Aluminum steel wrench and mounting hardware included No Barrel nut shims required for installation Weight: 14.7 oz 1.31" interior diameter 2.0 x 1.56 outer dimensions Full length MLOK slots at the 2 3 6 9 and 10 oclock positions Laser engraved T-marks Compatible with most known low profile non-adjustable and adjustable gas blocks Made & Assembled in USA Package Contents: Rainier Arms Rainier Industries Pro Series MK1 M-Lok AR-15 Handguard Barrel nut and hardware Rainier Arms RA022: Rainier Industries Pro Series MK1 M-Lok AR-15 Handguard Black 15 in