The ground glass was professionally replaced with a Brightscreen Proscreen. I'd estimate this is at least a few stops brighter than the standard Phase One ground glass - It's on par with a Hasselblad Acute-matte D screen IMHO. It has approx. markings for 37x37 & 37x49 w/ the extended markings for the stitching feature of this sliding back.

This is one of the highest quality stitching backs ever made (as one would expect from Phase One).

I sold my Cambo 4x5 cameras recently and decided to let this go as well, I hesitate as it really is a better sliding back than any other sliding back I've used from Linhof, Cambo and Kapture Group. 

GLOBAL SHIPPING THROUGH EBAY'S GLOBAL SHIPPING PROGRAM AT QUOTED RATES.