FN America SSR Rear Stock Adjustable Length FN SCAR 16S/17S Black. 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. Specifications for FN America SSR Rear Stock: Manufacturer: FN America Gun Make: FN Herstal Gun Model: FN SCAR 17S FN SCAR 16S Condition: New Features of FN America SSR Rear Stock Fits FN SCAR 16S/17S Toolless Adjustable Length of Pull and Cheek Height Features MIL-STD M1913 Rail on Bottom of Stock Package Contents: FN America SSR Rear Stock What firearm models does the manufacturer say FN America SSR Rear Stock is compatible with? The manufacturer suggests that FN America SSR Rear Stock is compatible with FN SCAR 16S FN SCAR 17SFN America 20-100566: SSR Rear Stock Adjustable Length FN SCAR 16S/17S Black