The Retro Wifi SI is an ESP8266 based wifi modem which when plugged into an old computer such as an Amstrad CPC (via Pace RS232) shows as a generic Hayes compatible modem. It allows the user to connect their Amstrad to WiFi and get on the internet such as using BBSes (Bulletin Board Systems) or telnet into other machines on the Local Network.
Availability and more information can be found here: https://www.simulant.uk/shop/retro-vintage-computer-wifi-modem-rs232-serial-hayes-compatible