(i) Mirror : Plain, inclinable with 3" steel C. P. stand.

(ii) Optical Slit : With fine machined cross slit, one surface white and the other optical black, with 3" steel CP stem. (iii) Nodal Upright : Consists of a combination of Single and Double lens holders on a mounting rotating along the vertical axis. The combination lens holder are adjustable in height and the single and twin lens holders can either be moved together by rack and pinion or relative to each other by sliding. These motions are read by individual pointers on a mm scale.The whole mount can rotate along its vertical axis and the degree of rotation read on a circular scale with 3" steel CP stem.

(iv) Lamp House : An electric bulb is enclosed in a metal case with cord and pin. It works on 220 V