Sea-Picro is a RP2040 based board in the Arduino Pro Micro form factor. LikeSea-Micro, it's designed to be a drop in replacement for keyboards wanting an upgrade from ATmega32u4 based pro micros.
Compatiable with most pro micro based keyboards
RP2040 microcontroller, with dual M0+ processors at up to 133MHz
Mid mount USB-C connector, which is low profile and can't be ripped off
OptionalElite-Cstyle pinout, adding an additional 5 IO for large keyboards
Single button reset / bootloader circuit which changes behavior based on how long it's held (RP2040 usually requires two buttons to flash new firmware, making it challenging when installed upside down in a keyboard)
ROM bootloader which prevents board from being bricked