ESP32 based board compatible with ESPectrum emulator, designed for inserting into ZX Spectrum 48k case (original or repro). This is the official web.
There are option to buy with or without case. For the uncased option you need to cut the case around the VGA connector. It supports both VGA and Scart video. The audio output is mono and the EAR input is not supported yet by the emulator. microSD not included. There are USB connectors for external keyboard and mouse, but the protocol is PS/2. So you need use dual protocol keyboard or PS/2 ones with passive adapter. Powering via microUSB cable (included with the cased option). On/Off switch near the power connector.
Demonstration video here (in Spanish):