Zamp Underwear Bottom - SFI 3.3 - Fire Retardant Blend - Black - X-Large - EachZamp Racings new Underwear Bottom provides an additional safety layer under your race suit. Made using lightweight, breathable materials, our underwear is what we suggest racers wear below their fire suits. Features include: FR Acrylic Cotton Blended 6. 5oz yd Single Layer Construction Large Cuffs prevent sliding under suit Breathable Material Plush Feel Tailored Fit prevents bunching, provides great fit SFI 3. 3 Approved Sizes Available: X Small,