Ruled Gratings, glass, not for intra cavity use:
148 grooves per mm, 5 Micron Blaze, 60 x 60 mm ruled (67 x 67 mm glass plate) SOLD
50 grooves per mm, 10 Micron Blaze, 60 x 60 mm ruled (67 x 67 mm glass plate), SOLD
147.5 grooves per mm, 4.0 Micron Blaze, 2.25 x 2.25 inch (57x57 mm), SOLD
1775 gooves per mm, visible use 50 x 50 mm. SOLD
$100 each, all for $225