Rainier Arms AR-15 Urban Combat M-Lok Handguard 15in Black Medium. Anti-Rotate QD sockets are provided on each end of rail at the 3 o'clock & 9 o'clock positions. Specifications for Rainier Arms AR-15 Urban Combat M-Lok Handguard: Manufacturer: Rainier Arms Color: Black Finish: Anodized Fabric/Material: 7075 Aluminum Gun Make: AR Platform Gun Model: AR-15 Gun Type: Rifle Inner Diameter: 1.315 in Mount Type: M-LOK Features of Rainier Arms AR-15 Urban Combat M-Lok Handguard Anti rotate tabs time Rail to upper receiver No Barrel nut shims required for installation Does not contact or apply side loads to gas tube Inner Diameter of handguard - 1.315 MLOK Slots at the 3 6 and 9 o'clock positions Barrel Nut diameter- 1.378 Compatible with most known low profile gas blocks Package Contents: Rainier Arms AR-15 Urban Combat M-Lok Handguard Rainier Arms RA-URBAN-ML-15: AR-15 Urban Combat M-Lok Handguard 15in Black Medium