RPK replacement hand guards rail system System adds four mil-spec Picatinny rails for versatile accessory applications Precision machined from 6061 T6 billet Aluminum for Maximum strength Fully rugged construction will not bend or deform under any condition Field tested under extreme conditions for maximum performance and durability Hard coat anodized for optimum wear resistance Simple installation, replace your hand guards and secured by 4 bolts No gunsmith required System aligns perfectly Slim profile for better grip and handling of the firearm The best solution for mounting sights and lasers