A laser light attachment for firearms and the like is disclosed. The attachment includes a housing for mounting to the handguard of a firearm, and contains batteries and a light source which may be visible or infrared, and contain one or more lasers of the visible or infrared spectrum type with windage...http://www.google.com.hk/patents/US5064988?utm_source=gb-gplus-share專利 US5064988 - Laser light attachment for firearms
