The Gates 2 1/2" Spanner Wrench adapts to a 3/8" drive ratchet or breaker bar to help you do your job faster and easier. The spanner lets you get a firm grip on the water pump pulley so that you can remove the fan clutch without scratching or galling the pulley or damaging the mating components. The Gates Spanner Wrench fits several Gates Water Pump pulleys including part numbers 43034, 43037, 45005, 45006 and 45010 which cover many popular Chrysler and GM applications.