The Sea-Micro is a fully open source Pro Micro alternative that replaces the Micro-USB connector with a USB-C connector. We have attempted to keep the cost of the controller as low as possible, while still retaining the follow key features: Mid mounted USB-C port Compatibility with all pro-micro powered keyboards ATmega32u4 controller DFU bootloader On-board reset button It has been tested on a wide range of split/DIY keyboards including: The Sofle, Corne, Helix, Contra, Revuing, Milk 2%. For split keyboard applications, it is possible to use the sea-micro as the master and your conventional pro-micro as the slave. The Sea-micro was developed by customkbd and JoshJoshua and is an open source project. Please find source files on Josh's github respository here. See a review of the sea-micro from Don (The Board Podcast) below: