This is tiny.
Amazing bit of homebrew.
The manual is in Japanese but the block diagram explains how it works
nifty bit of engineering with the case (3D printed and bent acrylic sheet). The PCB doubles up as support of the OLED and the uPC and battery charger are on separate PCB underneath. The components are gnat shite size though! This is some nice homebrew.
Looks like they are building some more...
Mine is 180mAH so lot smaller than original.