This is an intelligently designed, and well machined adapter. It has efficiently solved the insufficient in-focus problem which several valued eyepieces presented on a fast-Newtonian system, which makes the adapter well worth its modest purchase price. Would I recommend this item to another observer? Absolutely! As to purchasing from OPTcorp, It was a wholly positive experience.
This adapter works wonders for systems which do not have enough in-focus, particularly in H-alpha solar photography where either the camera nose is too long or the diagonal (i.e. Lunt takes up too much space. It fits beautifully into the recess of this adapter gaining a whole inch of in-focus (1/2 gain on zero ULA flange plus 1/2 recess into the device = 1. This apparatus is a boon to photo opportunity.