The Vulcan Chin Strap is designed to prevent hard hats from falling off, being bumped off employees' heads, and where there is a possibility of hard hats being dislodged due to high winds or awkward work positions (e.g. Bent over). According to OSHA, employees wearing hard hats and working at elevations create potential hazards for employees below. To protect workers below, OSHA requires employers to provide chin straps for the protective helmets worn by employees working at higher elevations, whether in an aerial lift or at the edge of a pit. Works with V100, V200, VF100 and VF200. Not compatible with VCB100 or VCB200.