These are originally from the estate of Louis Frederick Brehmer  (1868-1949) a professional photographer in the Rutland Vermont area. I sold one of his cameras a few yrs back, a Rochester Optical Co. New Model Improved Box Folding camera. Still finding some items in storage obtained from the family. Here you have 5 glass plate holders, 5" x 7"s. 4 are stamped on the side Rochester Camera Supply Co. Rochester NY. The 5th is identical to the marked ones. **Please check other listings for related items**