As part of the Simpsons Helix drive suit introduces its DNA not working with high-performance racing products.The spiral driving designed suit has a variety of features that enhance athletic performance with weight reduction and driver limitations applied to adult youth sizing SFI 5 rated DuPont NOMEX fabric 270 degree arm and back gussets, inner thigh stretch panel upper waist stress relief panel, ventilation port bulky back patch pockets and embroidered trim and the logo Simpson Suit Size Guide (GIF) Learn more about SFI and read the TPP Assessment Dell technical topic.What is SFI and TPP regulations?