Ryan Whitwam on Twitter: "I love the daughterboard for this keyboard. It tucks away in a little cubby at the bottom of the case. It's USB-C to connect the keyboard, and there's
USB PD daughter board for Famicom Power Adapter Board – Retro Game Restore
bitt101 - USB C daughter board – sagaklabs
Unified Daughterboard and JST Cable – CannonKeys
In-stock Unified Daughterboard and JST Cable | ThocStock