Specifications:
603707-1 Series have upright binocular head.
603707-2 Series have fixed binocular head, 45 angle inclined.
603707-3 Series have fixed binocular head, 45 angle inclined.
603707-5 Series have fixed binocular head, 45 angle inclined, 360 angle rotatable.
"A" type microscopes are built with same base and without any light.
"B" type microscopes are built with same base and with a top light.
"C" type microscopes are built with same base and with top and bottom light.