Dead Air Silencers Piston Spring for Ghost Odessa and Mojave 9 Black. This Spring is a replacement part. This spring is already included and ships inside the booster housing and piston on the Odessa Ghost and Mojave. The SD500 Booster Assembly already ships with a booster spring installed as well. Specifications for Dead Air Silencers Piston Spring for Ghost Odessa and Mojave 9: Manufacturer: Dead Air Silencers Color: Black Features of Dead Air Armament Dead Air Piston Spring for Ghost Odessa and Mojave 9: Piston Spring Installed Inside Replacement Part Included Ships Inside Booster Assembly Package Contents: Dead Air Armament Dead Air Piston Spring for Ghost Odessa and Mojave 9 Dead Air Silencers DA013: Piston Spring for Ghost Odessa and Mojave 9 Black