NAVIGATION
Potassium bromide crystal optic disc, 32mm x 3mm, polished both sides
Potassium bromide crystal optic disc, 32mm x 3mm (drilled), polished both sides
Calcium fluoride crystal optic disc, 13mm x 2mm, polished both sides
Calcium fluoride crystal optic disk, 25mm x 4mm, polished both sides
Barium fluoride crystal optic disc, 13mm x 2mm, polished both sides
Barium fluoride crystal optic disc, 25mm x 4mm, polished both sides