This is the Exhaust Stack for the Original Muffler that Went On the G4500. FEATURES: This piece mounts on the engine and then the original muffler mounted on it. The end of this piece is round and allowed the original swing muffler to be swung or rotated in the desired direction. SPECS: Length from manifold to end of stack: 1-1/4" Inside Diameter: 23mm (.91") Outside Diameter: 28mm (1.1") INCLUDES: One Aluminum Swing Stack Two Lock Washers Two 5x16mm Cap Screws ir/jl