To counter the pulley, V-belt pulley for mounting freewheel alternator, suitable for Bosch generators (not suitable for Valeo generators!)Material: chrome-vanadium steel, matt chrome-plated, 2-part nested, not separable. Bit front: multi-tooth XZN 10 mm, pulley holder multi-tooth XZN 33 teeth with 17 mm hex drive: 12.5 mm (1/2 inch), drive total length: 110 mm.