The Bosch 2600190052 Locating Washer is a replacement mechanical component for a wide range of Bosch Professional percussion drills, including GSB 18-2, GSB 16-2, GSB 20-2 and related RE, E and RCE variants. Bosch parts data confirms 2600190052 as a locating washer used within the compatible drill assemblies, making the exact machine number the best way to confirm fitment.