Oregon 35-003 Muffler for 2.5 to 3.5 HP Engines Tecumseh Part Numbers 27181B, 27181C and 27181A Replaces Tecumseh part numbers 27181B, 27181C and 27181A Measures 2-inches in length with a 2-1/4-inch outer diameter and has a 1-3/8-inch center to center