NAVIGATION
Sodium chloride crystal optic rectangle, 38.5mm x 19.5mm x 4mm (drilled), polished both sides
Potassium chloride crystal optic rectangle, 38.5mm x 19.5mm x 4mm, (drilled), polished both sides
Potassium bromide crystal optic rectangle, 38.5mm x 19.5mm x 4mm (drilled), polished both sides
Zinc selenide crystal optic rectangle, 38.5mm x 19.5mm x 2mm (drilled), polished both sides
Sodium chloride crystal optic rectangle, 41mm x 23mm x 6mm, polished both sides
Potassium bromide crystal optic rectangle, 41mm x 23mm x 6mm, polished both sides