Muffler 1w9519 Fits Caterpillar 953

1W9519, 1W9519-A. It features a square base plate with 4 bolt holes and is the style used on later serial number 953 machines (serial number prefixes 76Y1142-up, 5Z389-up, and 78Y828-871). Verify your serial number before ordering -- early serial number 953 machines use a different muffler design.