Simpson Underwear, CarbonX Ultimate Series, Shirt, Long Sleeve, Black, Medium, SFI 3.3/1

CarbonX® Ultimate™ underwear is made from double jersey interlock knit comprised of a patented blend of high-performance fibers and has extraordinary thermal protective properties. It is inherently flame resistant, will not burn, melt, or ignite when subjected to direct flame. Nomex® or CarbonX® Underwear underneath a racing suit will dramatically improve Thermal Protection Performance (TPP) in the case of an accident involving fire.