The Paccar Bellow Kit is designed for OEM numbers M66-7091-0335 and M66-6541-0335, offering a durable and reliable solution for Paccar trucks. Constructed from 321 stainless steel, the 4-inch diameter and 13.2-inch long bellow, along with the 4-inch diameter flange and flare, ensure a secure fit. Each kit includes one bellow, two rings, and two clamps, providing everything needed for installation. Sold by kit, this product is practical and convenient, fitting most Paccar trucks and comparing to OEM numbers M66-7091-0335 and M66-6541-0335.