EXO Series Protect-A-Boot Ringless are designed to withstand extreme racing and high heat environments. The outer exoskeleton of stainless steel mesh prevents direct contact with the dual layer silica boot underneath. This combination of silica/air gap and stainless steel provides outstanding heat protection for your plug boots and wires. Boot is surrounded by 304 stainless steel mesh Dual walled silica material improves heat dissipation Greater abrasion resistance 1 in. ID x 6 in. L No sewn-in ring 2-pack