The Fresh Air Systems Carbon-X Cool Shirt utilizes Carbon-X fire retardant fabric. These HANS compatible Carbon-X T-Shirts contain over 50 foot of small capillary tubing sewn onto the front and back. Get the best of both worlds - driver comfort without sacrificing driver safety! Note: Fresh Air Systems Cool Suit Shirts are not compatible with 2012 and later CoolShirt systems. An adapter is needed to use this shirt with these CoolShirt systems.