The Er: YAG laser (2940nm) impacts water. It has an extremely high affinity for water and so it is the laser of choice in the removal of superficial skin lesions. It removes the skin and is also defined as a “cold laser” because it only releases a tiny quantity of heat into the tissue. It is not able, therefore, to coagulate but it is extremely useful in removing very superficial lesions or carbon residues that are often left behind after treatments with CO2 laser.