i) Prism: Reading printed on horizontal face of compass ring can be read from vertical position
ii) Lifting pin: When the instrument not in use the sight vane passes against the lifting pin which lift the needle off the pivot and holds it against a glass lid ; thus it prevents the undue wear of pivot point
iii) Prism cap: Provided at the bottom of prism, closes window of prism when not in use
iv) Agate cap: A small piece of hard glass provided on top of pivoted point, to reduce wear and tear of the point