The RW-4 line of undergarments are designed to provide both comfort and protection. The RW-4 features a soft-touch interlock fabric. Then RW-4 includes long-sleeved undershirts, long underpants, a hood with a single opening and mid-calf socks. The hoods are one size fits all; undershirts and underpants are available in sizes Small through XX-Large. The RW-4 undershirts and underpants are regular fit. Socks are available in sizes from 38/39 to 46. The RW-4 line is FIA 8856-2018 approved.