Protect-A-Boots XL Ringless solve the problem of burning and cracking plug boots and wires from header and engine heat. Protect-A-Boots are made from a high temperature resistant glass fiber material and treated with a proprietary coating, Protect-A-Boots XL Ringless provide spark plug boot and wire protection from extreme under hood heat and helps prevent burn-through, hardening and cracking of boots. For thicker boots, like MSD or Taylor's, we recommend our Protect-A-Boot Ringless Sleeves; the 1.25'' diameter will allow for a simple install. Non-flammable & protects against chemicals & resists water 1 in. I.D. x 8 in. length Universal - fits most straight or angled boots Double-wall construction for added durability