The SilencerCo Hybrid piston housing is comprised of three separate parts. The Piston Housing, the Piston Spring (Sold Separately), and the Piston (Sold Separately) to match your particular firearms thread pitch. This kit includes just the housing. Made from high quality steel and featuring a matte black finish this housing will be ultra durable. This housing is compatible with the SilencerCo Hybrid suppressor.