I have the main unit with tree modules.
type handheld game console
Interchangeable — Multi-Game Console
This ”Interchangeable” device was a budget game console offering multiple game variants through interchangeable cartridges or built-in game selection — one of the many simple gaming devices produced during the late 1970s and early 1980s that competed in the lower end of the home gaming market. The name directly described its key selling point: the ability to switch between different games, distinguishing it from single-game dedicated consoles. These budget multi-game devices represented an important step in making programmable home gaming accessible to cost-conscious consumers before the major cartridge-based console platforms established their dominance.