Impact Racing 10000021 Acc - Skirt, 2 Layer, Tapered, Sewn In, SFI 3.3/5. Add valuable seconds of thermal protection while reducing wind noise to your communication system with Impact’s two or three layer helmet skirt. Available pre-installed (built-in) at the factory in your Impact helmet or as a do-it-yourself hook-and-loop attachment, our helmet skirt is manufactured from a soft knit Nomex® providing added protection from heat transfer while also reducing dirt and debris from entering the helmet. The 2-layer skirt is available in our standard or tapered-in design. The tapered-in design allows the skirt to be tucked into the driving suit more easily while reducing interference between the skirt and frontal head restraint device.