This is the T-2080C Tuned Silencer Set for the O.S. 21XZ-R Version II ABC Engine, OSMG2042. FEATURES: Constructed of aluminum with polished natural finish INCLUDES: Silencer with Pressure Nipple (OSMG2984) Manifold (OSMG2716) Engine to Manifold Silicone Gasket Manifold to Silencer Silicone Gasket Three Manifold to Silencer Short Springs Two Silencer to Engine Long Springs REQUIRES: Assembly and fastening to engine SPECS: Length: 6.4" (163mm) Diameter: 1.4" (36mm) jxs 10/26/11 ir/jxs