Carbon X Underwear Top X-Large Long Sleeve

The Carbon X Underwear Top X-Large Long Sleeve from Simpson Safety is purpose-built for high-performance motorsports and automotive work where fire protection is non-negotiable. Designed to meet SFI 3.3 certification standards, this crewneck base layer serves as the critical first line of defense against thermal hazards during racing, track days, and shop environments where ignition risks exist. Whether you're a professional race driver, weekend competitor, or serious automotive enthusiast working in high-heat conditions, this fire-resistant underwear top provides the protection you need to focus on performance without compromise.

Constructed from CarbonX material, this long-sleeve top delivers superior thermal barrier properties that exceed standard cotton or synthetic alternatives. CarbonX fiber is engineered specifically for motorsports applications, offering excellent flame resistance while maintaining breathability and comfort during extended wear—critical when you're spending hours in a cockpit or under the hood. The black colorway resists visible wear and staining common in automotive environments, while the fitted X-Large sizing ensures proper contact with skin for optimal heat protection without excess bulk that interferes with safety harnesses or protective suits.

This SFI 3.3-certified base layer is essential for anyone operating a high-performance vehicle or working in professional motorsports settings where fire-resistant gear is mandated or strongly recommended. Worn beneath driving suits, race suits, or fire-resistant outer layers, the Carbon X Underwear Top provides a complete thermal protection system that meets sanctioning body requirements. The long-sleeve design and crewneck configuration maximize coverage, making it compatible with full-face helmets and safety harnesses without gaps or exposed skin. Stack this with a matching fire-resistant suit for comprehensive protection that meets or exceeds track and competition standards.