Laser Lenses, Optics, and Focus - LaserGods
Nov 24, 2019· Lenses are typically referenced by their focal point. The most common lens, and the one that is shipped with the K40, is the 2.0″ or 50.8mm lens. This refers to the focal point or distance between the lens and the work. it does not refer to the diameter. The diameter of a standard K40 lens is 12mm.