NecksGen Wedge Frontal Helmet SupportDesigned with soft foam to fit with your REV Head and Neck Restraint, this frontal collar helps stabilize your head and helmet to prevent fatigue and neck strain over long races or rough terrain. The washable SFI 3. 3 rated FR cover has an adjustable hook and loop flap at the back so you can adjust how tightly youd like it to sit against your neck.