QL Trackball

QL Trackball is a fairly standard version of a trackball (also called the Command Control), produced by Wico Corporation and initially aimed at Atari home video games, then making it onto Commodore Vic-20,Apple II and TRS-80 home computers.

A trackball is almost like an upside down mouse, where you move the ball around with your fingers in order to control the joystick or cursor on screen.

This appears to have only been released in the US market - it has a standard Atari style joystick connector (OK for US and European QLs), but which would need a joystick convertor on the UK standard QL.

The unit is also powered with a 6V power supply.