The firmware v1.0.3 of the Imperium Solo by Duke is available. It's an adaptator to use USB joysticks (PS4, Xbox One...) on a standard joystick port of an Amstrad CPC (and later ZX Spectrum, C64, Amiga and Atari ST).

The split cable which the CPC and the adaptator is included for the price of 15 euros, add shipping and paypal cost too.