Designed with billet bulkhead pinsBillet bulkhead pins give greater durabilityUsed on "pressed on" water pump pulleysUsed on many 2000 and later GM trucksMade in the U.S.A. This specially designed four pin tool, with cormoly billet bulkhead pins, is used on vehicles using pressed on pulleys. The four strengthened pins in this tool give the professional technician greater durability than tools presently available on the market. These pressed on pulleys have holes instead of bolt heads for use in securing the pulley from rotating while removing or installing the fan clutch assembly. With the use of a 48 mm open end wrench part #95210 the technician can loosen and tighten the fan clutch on many 2000 and later G.M. trucks. Used on the following applications: G.M. 6.5 Liter diesel engine 2000-2001. G.M. / Isuzu-Duramax 6.6 Liter diesel engine 2001-2005 G.M. / Isuzu-Duramax 6.6 Liter diesel engine with new pin bar fan hub 2006 and later.