The Menacer is a wireless lightgun created by Sega for the Sega Mega Drive/Sega Genesis video game console in 1992, as a response to the Super Scope by Nintendo. The Menacer is made up of three interconnected sections. The main section alone can be used as a pistol. A skeletonized shoulder stock can be added for extra support. The third removable section are twin sights that are clipped on to the top of the barrel. The twin sights were impractical, as one could not effectively see what one was shooting at.
The Menacer is powered by 6 AAA batteries and was not connected by a wire to the console but by an infrared beam that relays signals to a receiver box that would ideally sit on top of the television. The receiver box has to be plugged into the console in the second controller port. The Menacer was advertised as the most accurate light gun ever. The Menacer retailed for $100 in North America.
The Menacer came with an exclusive 6-game cartridge of mostly target shooting games. The games included on the cartridge are: Pest Control, Space Station Defender, Whack Ball, Front Line, Rockman's Zone, and Ready, Aim Tomatoes! -- the latter stars Sega franchise characters ToeJam and Earl. While most games utilize the light gun as a means to shoot down objects, Whack Ball actually utilized the Menacer as a mouse of sorts. All 6 of the games were conceptualized by Mac Senour, Producer on both the hardware and software. The Menacer works fully with the Sega Mega-CD, even though that system had, with the Konami Justifier, two different light guns developed for it.
Since the Menacer uses scan lines to determine where the user is aiming, it will only work with CRT based television sets. It also won't work with frame grabber cards or TV tuners that redirect the output to a computer screen.
Sega and third-party developers did not develop many games for the Menacer. The only compatible Mega Drive games were the 6-game cartridge, Body Count, and T2: The Arcade Game. All other Menacer games were for the Sega 32X and/or Sega Mega-CD.
Source: Wikipedia, "Menacer", available under the CC-BY-SA License.