The RaceQuip SFI Rated 360 Degree Helmet Support Neck Collar is made of high-density flame retardant foam which is covered with a woven FRC fabric. Used in auto racing to hold the helmet up off the driver's shoulders and provide a cushion between the helmet and shoulder blades or chest. The round tapered wedge design measures 1 3/4" tall in the front and 2 1/4" tall in the rear. The fully closed measurement allows for up to a maximum neck size of about 17" and it can go up to approxiamtely 20" if a gap is left in the closure so the RaceQuip Helmet Support Collars are comfortable and easy to use. Exceeds SFI 3.3 certification with SFI tag affixed. Available in black, red, and blue.