Type 1 OM904 OM906 Piston Ring Set 1 Cylinder for Mercedes-Benz Atego, Axor, Econic Product Description: Bore: 102 mm Ring thickness: 3.0 (Top ring), 2.5 (Middle ), 4.0 (Oil Ring) Suits the multiple models please see compatibility table OEM Part Number Reference- 003 030 97 24 904 030 00 24 906 037 06 16 906 037 08 16 906 037 08 18 906 037 10 16 A003 030 97 24 A904 030 00 24 A906 037 06 16 A906 037 08 16 A906 037 08 18 A906 037 10 16 Please, note , there are 2 types of Piston Rings for the OM904. This is the later type. Please be sure to check the compatibility table , and if unsure, send us your Registration / VIN number and we can check it for you.