Wera Zyklop 3/8" Hex socket bit w/ holding function US sizes8740 B HF. 3 8" drive for Hex (Allen head) socket bolts screws. These socket bits come with holding function and Hex Plus bits; offering a larger tool to bolt contact to prevent bolt damage. Compatible with all hex (Allen head) bolts. Chrome vanadium with a brushed chrome plated finish and color coded for finding the right size quickly. Knurled at the base for easier manual turning. With ball intercept ring. Note: Not compatible with impact wrenches.