Insul-Boot

Natural fiber glass spark plug heat shield

American Made Since 1985

Insul-Boot

Original Design. Unmatched Reliability

Protect your ignition system with the original spark plug boot heat shield trusted by professionals. Insul-Boot shields withstand up to 1200°F, prevent misfires, and extend plug wire life—even in direct contact with headers or manifolds.

Reflects and dissipates radiant heat for improved performance
1 inch inner diameter fits most spark plug boots, including 90° styles
Durable double-wall construction for maximum heat protection
Made in the USA with high-quality materials

1200°F

649 °C

Continuous

2000°F

1093 °C

Intermittent

Instruction Sheet

Brochure

Product Types

400200

1 Id x 6 in Tan (2 Pack)

400201

1 ID x 6 in Red (2 Pack)

400202

1 in ID x 6 in Blue (2 Pack)

400204

1 in ID x 6 in Black (2 Pack)

400800

1 in id x 6 in Tan (8 Pack)

400801

1 in ID x 6 in Red (8 Pack)

400802

1 in ID x 6 in Blue (8 Pack)

400804

1 in ID x 6 in Black (8 Pack)

Insul-Boot – The Original Spark Plug Boot Heat Shield

Protect your ignition system with the original spark plug boot heat shield trusted by professionals. Insul-Boot shields plug wires and boots from extreme heat—up to 1200°F—even in direct contact with headers or manifolds. By reducing heat exposure and preventing burnout, these boot covers extend wire and boot life while improving ignition performance and reducing the risk of misfires or engine damage.

Durable Construction for Lasting Protection

Built with a double-wall fiberglass construction, Insul-Boots are specially heat-treated to reflect and dissipate radiant heat. The universal fit works with most boot angles, and they’re available in natural tan and high-temp ceramic-coated red, blue, and black finishes. A built-in metal retention ring ensures each heat shield stays securely in place—preventing it from sliding up the wire and exposing the boot to heat. These easy-to-install spark plug boot protectors won’t interfere with plug changes, giving you peace of mind and long-lasting performance.