Here are Lieutenant Paul Stamets spore drive implants. Designed for CR2032 battery with holder and mini SPDT PCB switch and 5mm LED (I used blue one). To attache it to your hand use 15mm wide strip of plastic band and double sided tape.
There is a version for dual nozzle printer (black and clear PLA works best), but also single print model which you can paint after.
Physics, 3D printing, Programming, Astronomy and Sci-fi - that's me \//