Master Gear
![A Master Gear with its plastic enclosure removed.](/Images/godic/202501/26/Exposed_Master_Gear_Circuitry2353.jpg")
The Master Gear, Master Gear Converter, or Master Gear Adaptor is a handheld game console peripheral invented by King-Ho So for Kalplus Limited with the purpose of allowing 50-pin Master System cartridges to fit into and function on a Game Gear.