INJECTOR SEAT CUTTER SET (8 PIECES) Cleaning the injector seat of carbon deposits and corrosion is essential before each injector is reinstalled in the block. This prevents leaks, which can cause the seat to burn out and damage the engine block. KIT COMPOSITION: 15 x 19 mm- flat reamer (universal) 17 x 17 mm- angle reamer (Mercedes Benz CDI) 17 x 17 mm- flat reamer (Delphi / Bosch - BMW, PSA, Renault, Ford) 17 x 19 mm- flat reamer (Bosch, Mercedes CRD) 17 x 21 mm- angle reamer - Fiat / Iveco 1 x "Pilot" T-handle driver