Seekins Precision NOXs M-LOK Rail, 15, Not Compatible With the AR-10 Platform, Fits AR-15 Rifles, Black 0010530053 Designed to eliminate weight and unnecessary material" the Seekins Precision NOXS handguard provides superior handling performance to the modern sporting rifle platform at an exceptional value. The unique NOXS handguard design has an extremely thin profile" lightweight construction and is simple to install with basic hand tools. Machined from 6061-T6 aluminum with an integral top rail" additional features include four QD sling mounting points and M-LOK accessory mounting slots along the length of the tube. The NOXS is the perfect handguard for competition" sporting applications or extreme duty use. Includes barrel nut and mounting hardware. Inside diameter: 1.35"