The Mack Insulator Kit is a high-temperature polyurethane kit that provides excellent insulation for your vehicle. Sold as a kit, it includes 8 PL1017-HT insulators, 8 washers, 4 3/4"-16 x 5" bolts, and 4 locknuts. This kit is designed to fit OE parts such as Gaff 12035, Mack 204SX389 (Rear Engine - Fuller & Allison Transmission), and PAI FKT-5069. With its durable construction and easy installation, the Mack Insulator Kit is a practical solution for maintaining optimal performance and reducing heat transfer in your vehicle.