Ruled Gratings, glass, not for intra cavity use:
60 x 60 mm, 148 grooves per mm, 5 Micron Blaze
60 x 60 mm, 50 grooves per mm, 10 Micron Blaze
50 x 50 mm, 147.5 grooves per mm, 4.0 Micron Blaze
50 x 50 mm, 1775 gooves per mm, visible use.
Take all for $300