This is proto2040, an rp2040 based board. But why's it special? It's so small! So small and thin but without compromises. All the GPIO is routed to 1mm headers, with separate ones for ADC labelled accordingly! - as a result you can access all SPI, I2C and UART peripherals you might need and power giving you access to 3.3v, GND and 5V. If you need to make it thinner, there's two things you can do. You can desolder the USB-C port, and solder to the USB data lines exposed on a separate PCB header. You can also use hot air to replace the SOIC8-W flash chip with a thinner, UDFN-8 one - the footprint for that one is hidden under the large flash chip. This will help you bring board thickness even further down, for any space-constrained application being able to embed it into smallest of places, wherever you need a small microcontroller, whether it's some tiny trinket of yours, perhaps an art piece, or a mod chip to make your devices do something they're not designed to do.