Ideal tool for assembling and dismantling the free wheel pulley whilst charging the alternator or pulley on Bosch alternators Star is the equivalent of Torx - 6 sided Torx is the registered trademark of Acument Intellectual Properties, LLC The pulley shaft is held in place with the T50 Star bit on 1/2in.D socket whilst the nut is undone using the 33 teeth union nut with 19mm spanner