Originally Posted by mike c
Do not know what enlarger you have but the B-66 is for med format negs 6cm x6cm, it would be to small for a Omega D series (4x5) enlarger.
I know, but I'm not sure it's really for the B-66 as I can't find any reference for a zone vi head designed for that enlarger.
It would have to be pretty small to fit in a B-66. That looks like an assembly for an early D series. (I could be, and often am, wrong)