The FN SCAR SSR Rear Stock is the ultimate precision upgrade to your SCAR 16S and 17S, allowing you to quickly convert your carbine into a DMR-style rifle that is fully adjustable for length of pull (LOP) and cheek height. No tools required! Designed to improve user ergonomics while shooting from the supported prone position, the SSR Rear Stock can be adjusted for length of pull by pushing in on the adjustment lock, extending or collapsing the buttpad to the desired position. The cheek height can be adjusted by pressing in on the cheek rest riser and pulling upward until you reach the correct height. It also features a MIL-STD M1913 rail for attachment of monopods or other accessories that aid supported shooting positions.Features :Fits FN SCAR 16S/17SToolless Adjustable Length of Pull and Cheek HeightFeatures MIL-STD M1913 Rail on Bottom of StockBlack