This Cessna 152 Exhaust Muffler/Heat Exchanger Part Number 0454009-5AWL is a replacement for Cessna part number 0454009-5 and 0454009-1. This muffler is also used in next higher assembly 0454011-1 and 0454021-1 Exhaust assembly and the 0454011-200 Muffler and Riser. Exhaust assembly 0454021-1 is physically interchangable with 0454011-2.This Cessna 152 Exhaust Muffler/Heat Exchanger is typically Equipped on the Following Serial number Aircraft: Cessna 152 Aircraft:15279406-15286033, A1500433, 681, A1520735 - A1521049, Riems F152 Aircraft F15201429 - F15201980, FA1520337- FA1520425