English: From the website: " U.S. Marine Corps Lt. Heath Clifford, with Marine Aircraft Group 29, uses a mirror to signal a MV-22B Osprey aircraft during a tactical recovery of aircraft and personnel exercise at Al Asad Air Base, Iraq,Oct. 23, 2007. (U.S. Marine Corps photo by Cpl. Michael Haas) (Released) Location: Al Asad Air Base VIRIN: 071023-M-2166H-002" This mirror is a 2"x3" acrylic military issue mirror, National Stock NSN 6350-00-105-1252, description MIRROR,EMERGENCY SIGNALING 2"x3" Acrylic The aimer is made of retroreflective cloth with a (patented, trademarked) star-shaped sighting aperture. Retroreflective aimers are like a reflex gunsight – they produce a bright round fuzzy “fireball”, visible only when looking through the aimer, in the direction of the reflected light. The principle of using a retroreflective sheet coplanar with the mirror was invented by Richard S. Hunter, who filed for a patent on April 20, 1945, which was issued as US Patent 2,412,616 on Dec. 17, 1946. That patent is viewable online at http://www.google.com/patents?vid=USPAT2412616 , and provides diagrams and explanations of the aiming principle. This type of signal mirror also floats, and the general construction has much in common with the signal mirror described in U.S. Patent 3,164,124 to Frederick Ehrsam, issued Jan. 5, 1965, and viewable online here: http://www.google.com/patents?vid=USPAT3164124 .