The Sega Game Gear is an 8-bit handheld game console released by Sega on October 6, 1990 in Japan, 1991 in North America and Europe, and Australia in 1992. The Game Gear primarily competed with Nintendo's Game Boy, the Atari Lynx and NEC's TurboExpress. The handheld shares much of its hardware with the Sega Master System and is able to play its own titles as well as those of the Master System, the latter being made possible by the use of an adapter. More: en.wikipedia.org.