Impact Racing 78900413 Underwear - Top, Long Sleeve, Yth Med, Gry. Gain valuable additional seconds of heat and thermal protection with the use of Impact’s fire retardant base layer manufactured from our line of lightweight ImpactMAX soft-knit aramid fabric and available in a natural white or charcoal gray. Our soft yet durable fire retardant underwear is form fitting and hand-crafted with a flat interlock stitch to minimize pressure points while providing cooling comfort through the use of our exclusive moisture-wicking aramid fabric. Available in long sleeve tops and full-length pants, Impact’s works perfectly under any driving or crew suit and provides an additional layer of valuable protection. Adult Sizes: XS/S/M/L/XL/2X/3X