The Game Gear is an 8-bit fourth-generation handheld game console released by Sega on October 6, 1990 in Japan, in April 1991 throughout North America and Europe, and in 1992 in Australia. The Game Gear primarily competed with Nintendo's Game Boy, the Atari Lynx, and NEC's TurboExpress. It shares much of its hardware with the Master System, and can play Master System games through the use of an adapter.