Simpson’s Hybrid frontal head restraint is an important part of any racer’s safety arsenal. SFI 38.1 certified, FIA 8858-2010 approved on screen text But like any safety equipment, a Hybrid must be used within its design parameters to ensure proper function. The proper way to adjust Hybrid tethers is by shortening or lengthening the two tethers that extend up from the devise and attach to the helmet anchor. Hybrid devices can be attached using your choice of one of the four anchor options offere