Clamp-On Heat Shields incorporate Thermo-Tec's proprietary coating technology developed by Thermo-Tec, Thermal Conduction Technology. The new and improved flexible Clamp-On Heat Shield blocks over 95% of the damaging radiant heat of the exhaust.The high-tech composite construction of this heat shield provides the ultimate in protection. The kits come complete with all clamps and new stainless stand offs and installs in minutes. Clamp-On Heat Shields are available in one, two and three foot lengths.For exhaust pipes that exceed 3.5", use the 4" clamps of which will accommodate up to 4.5". For motorcycle and applications involving smaller pipe, consider the 11650 and 11660 of which are designed for 2" exhaust.