This photo shows a military surplus laser rangefinder blasting a hole in a block of rubber. The laser head itself, on the right, is about 4 inches long. There is a collimator in the center containing three lenses; one to expand the 5 mm beam, another to focus it to a smaller diameter (0.5 mm), and a third to straighten the smaller beam. Although the laser beam itself is invisible infrared radiation, the effects can easily be seen as a burst of plasma-hot, vaporized rubber erupting from the block with a loud 'snap'. The laser is operated at 45 joules of input energy (3 times its designed power) using a special PE flashtube not supplied with the unit. The laser is able drill a 0.5 mm hole through 3/8" of nitrile rubber, or 5 Gillette razor blades in a single shot. (Equivalent in thickness, it can drill a Stanley box-cutter blade in one shot, or a utility knife blade in five.)