This aluminized end in - end out centered muffler is a reliable replacement for OE M66-6188 and M101451. With its aluminized finish, it offers durability and protection against corrosion. It features a 5-inch inlet inner diameter (Measurement A) and a 5-inch outlet inner diameter (Measurement B), making it compatible with most makes and models. The 10-inch body diameter (Measurement C) and 44.2-inch body length (Measurement D) ensure optimal performance. With a 49.5-inch overall length (Measurement E), this muffler is practical and efficient. Sold individually, it is a Paccar replacement for OEM M66-6188 and M101451.