Fore sight
Back sight
Intermediate sight
Height of instrument
Staff reading
Invar staff
Telescopic staff
Folding staff
Target staff
R.L of Bench mark + Back sight reading
R.L of Bench mark ? I.S reading
R.L of Bench mark ? F.S reading
R.L of Bench mark ? Back sight reading
The line of collimation
Horizontal line
Vertical line
Slant line