The STS (Skeleton Traditional Stock) Buttstock introduces a more traditional rifle ergonomic and form to the world’s most modular precision rifle chassis, the LSS GEN3 Chassis System. Built for shooters who want the precision and modularity of a chassis while keeping a more classic stock feel and function, the STS delivers both. Repeatable comfort and real-world conditions, without compromising on adjustability or rigidity. *NOT compatible with Ruger American or Ruger 10/22