Chrome vanadium. 1/4″ hex drive security bits compatible with most tamper proof fastener systems. Includes 17 x 75mm long bits, 79 x 25mm bits, 60mm bit holder, and 25mm connector. Carry case. Chrome vanadium. 1/4″ hex drive security bits compatible with most tamper proof fastener systems. Includes 17 x 75mm long bits, 79 x 25mm bits, 60mm bit holder, and 25mm connector. Carry case.