This is the 7/16" Muffler Extension for the #761 & the #871 OSMG2814 mufflers This Muffler Extension is a 7/16" spacer that installs between the muffler and the exhaust port on the side of the cylinder head. This results in the muffler being farther out from the cowl of the plane. One might elect to use one of the muffler extensions to keep the fuel residue farther out from a prized paint job or if the aircraft has a large cowl and the muffler isn"t far enough away from the outside of the cowl. This fits the: .10FP, .10FP-B, .10FP-BX, .10FP-S, .12CZ-1, .12CZ-2, .12CZ-R, .12CZ-Z, .15FP, .15FP-S, FEATURES: Natural aluminum construction INCLUDES: One 7/16" (11.5mm) Muffler Extension Two 2.5x36mm round phillips head steel screws w/.45 pitch threads Two 2.5x34mm round phillips head steel screws w/.45 pitch threads OSMG6951 SPECS: Length: 11.5mm Width: 33.7mm Height: 7.6mm Distance between mounting hole centers: 27.5mm Port Width: 16.6mm Height: 4.6mm COMMENTS: For 90° adapter use OSMG2596 JAL 5/12/98up ir/jl updated tjt 042905