a) Prism Type : Lemon optical glass prism specially designed hangs over the eye-piece of the microscope. The pencil on the graph is visible moving on the image is drawn on the graph, very compact in design, Prism will be silver coated one side and it will be packed in velvet box.
b) Mirror Type : with this unit it is possible to draw the image seen in the microscope. The mirror reflects the pencil point image into an abbe prism clamped over the eye-piece and superimposes it up on the. specimen image. The prism box is hinged for quick change of eye-piece for normal observation complete in velvet box.