RST Thermal Wind Block fabric offers more than just wind protection; the ergonomic design is enhanced by a four-way stretch material with stretch and compression properties. This helps keep the muscles warm, reducing muscle strain and rider fatigue. The breathability of Thermal Wind Block also keeps you as comfortable and as warm as possible. As with all RST products, RST Thermal Wind Block garments have been tested by our development team in the toughest weather the UK has to offer.