[ClinA-78]

Hello,

Pawel, I presume this is the part number (cf Roger's first input), but don't know what is the meaning of '.51';
However I have noticed also a Ju 88 R-2 equipped with counterweight, so would it be also a matter of particular engine, not only related to ETC and 'boosting' system? Never seen a counterweight on woodden blade from a Jumo 213 for instance, why?

Best regards

ClinA-78