Product Description Fitment: Spanner Wrench fits most plastic retaining rings. It's compatible with all vehicles that have silent fuel tank lids 3/8-inch to 1/2-inch (38mm to 168mm) in size. Application: Fits for Mercedes-Benz, BMW, Audi, Volkswagen (VW) and Chrysler vehicles. Function: Used with 1/2" drive ratchet or breaker bar. Easily remove and install Fuel Pump Retaining Rings! Perfect Design: The wrench easily engages in the ridges around a threaded locking collar that secures the fuel pump to the top of the tank. .