This is a Bolt-On Pitts Muffler for the OS 40SF, 46SF, .40FX, .46FX, 46AX, .50SX and 55AX Engines.Pitts-Style Mufflers are used on engines that are Side-Mounted (lying on theirside) Inside a Cowl. This routes the exhaust out the bottom of the cowl.INCLUDES: Pitts Muffler (with brass pressure fitting installed)SPECS: Overall Width: 3-3/16" Overall Depth: 1-3/4" Height (not including exhaust tubes): 1-1/4" Length of Exhaust Tubes: 2-7/16" (may be cut shorter) Tube Outer Diameter: 7/16"REQUIRES: This muffler does not come with the mounting screws, use the screws that come with the engine (or use OSMG6914)COMMENTS: Comes with a One-Year Warranty.BissonPart BIS04046