Description The RW-4 NON-FIA/SFI line of undergarments use the same exact material as the homologated RW-4 undergarments, the only difference is the undergarment configuration. The FIA and SFI do not homologate short sleeved shirts, boxer short lowers and single layer balaclavas. The NON-FIA/SFI RW-4 undergarments are an option to drivers who are not professionally competing but would still like more protection for track days. TECHNOLOGY Soft and comfortable Regular Fit NON-FIA/SFI.