24 Jul Vintage Bausch & Lomb 33-52-20-44 diffraction grating Grooves 600mm 30×25 mm
Vintage Bausch & Lomb 33-52-20-44 diffraction grating Grooves 600mm 30x25 mm Manufacturer: Bausch & Lomb Incorporated, Rochester, N.Y., U.S.A. Catalog No.: 33-52-20-44 Serial NO. 2229-14 Specifications: 600 grooves/mm with a 7°55' blaze angle Sold as pictured...