To ream out and clean the bore between the glow plug and pre-combustion chamber.

A:

For pre-heater plugs with 10mm across flats on mercedes CDI enginee(OM611,612,613etc)

For pulling out pre-heater plugs after have been unsrewed but are still located girmly in their holes.

Length:135mm

Drive:19mm hex

B:

Application:Mercedes 4-Valve-engines OM604,OM605, OM606 with glow plug threads

Size:M12 X 1.25

Drive:13mm hex

Glow plug:7mm

C:

Important if the engie is difficult to start.

Application:Meredes CDI-Engines 4.5 & 6

ylinder OM611,612,613 with Glow plug threads M10 x 1

Drive:10mm hex

Glow plug:6mm