Positioning lasers simplify the alignment of workpieces. For this purpose, they are mounted on or over machineries or work tables. A laser line indicates then on the workpiece the correct position. As a result, work procedures are simplified and working stages are stated more precisely. The lasers are available with different optical systems such as dot, line or cross. Depending on the model, power supply will be ensured by batteries, AC adapter or by direct connection to the machinery.