The hand level is widely used for taping and for the rouge determination of elevations. It consists of a metal sighting tube on which in mounted a bubble tube. If the bubble is centred while sighting through the tube, the line of sight is horiziontal. Actually, the bubble tube is located on top of the instrument and its image is reflected by means of a 45º mirror or prism inside the tube so that its user can see the bubble at the same times as the terrain. The hadn level is very useful to surveyor for holding the steel tape horizontal.