A handy laser pointer including a cylindrical cassing coated with a layer of phosphorescent substance and having a transverse through hole, a laser firing cap fastened to the front end of the casing by plugging, a rear end cap fastened to the rear end of the casing by a screw joint and having a hanging...http://www.google.es/patents/US5697700?utm_source=gb-gplus-sharePatente US5697700 - Handy laser pointer
