In need of a new set of pulley wheels, I ordered a set with sealed bearings. They made no mention of size nor limits in use.
Anyway, the package marking suggest these were made for the 8-10 speed range, whereas my needs fall into the 6 & 7 speed category.
The pulleys come with various fitting hardware, so they fit into the vintage Campagnolo Nuovo Record RD and seem to fit well.
Is there any reason that such pulleys, made for 8-10 speed chains, should not be used with a 6-speed drive?
FWIW, the brand of the pulleys is Tacx Jockey Wheels.