Hard Hat Adapter, Color Black, Compatible with Brand Optrel, Compatible with Grainger Part Number 35T252, 35T253, 35T255, Compatible with Manufacturer Model Number 1006.210, 1006.300, 1006.500, 1006.501, 1006.502, 1006.600, 1006.900, 1006.901, 1007.000, 1007.011, 1007.200, 1010.000, 1010.100, 1010.200, 1010.201, 1100.000, All Optrel Helmets, Features Universal