The Franklin Armory FSR handguard is offered in multiple sizes (11.5 13 and 15) that features a four picatinny sides on both the front a rear of the handguard. The three sided smooth midsection is both ergonomic and comfortable but also can accept many name brand rail sections for additional accessories. - SPECIFICATIONS: - Free Float & Vented Handguard - Ultra narrow comfortable and easy to grasp midsection - Utilizes Picatinny Rails at front where needed - Full Length Picatinny Rail on Top - Closed Ports Adjacent to Gas Block Location for Safety & Comfort - Two QD Sling Mounts on each side - 6061-T6 Material - Hard Coat Type III Anodized Black - Barrel Nut Included - WEIGHT: FSR 13 Handguard 16.5 oz.