Galvanometers (also called "galvo scanners" or "scan heads")are computer-controlled electromagnetic devices that move mirrors mounted on the end of rotary shafts. The mirror reflects the laser beam to "draw" images. Galvanometers are typically identified by their speed of operation, measured in Kpps (kilo points per second). Each galvanometer moves the beam in one plane, either X axis or Y axis. Placing the galvanometers close together at 90 degrees to each other allows full movement of the laser beam within a defined square area. The most useful specifications of a galvanometer pair for laser show , laser marking, laser engraving, laser cutting, 3D printing and Skin resurfacing applications. The galvanometer is controlled by a servo system��the control circuit uses a feedback signal generated by the mirror's motion to correct motion commands. An amplifier similar to an audio power amplifier drives the mirror.