It sort of clips to the cover of the book, has a compartment to house the electronics, can use whatever led and components you like, this is just what i had on hand. Its surprisingly stronger than it looks. I printed it in pla+. I intentionally used a 47ohm resistor to make it softer and nicer to read under, but if you want it brighter use a 33ohm or maybe even 20ohm resistor. This one is powered by a 3.7v 18650 battery. Origonally i wanted a switch but i broke my switch and just decided to plug it directly into the charger. https://www.amazon.com/dp/B07D3SQYKJ?ref=ppx_yo2ov_dt_b_fed_asin_title This post only has the base that i made, get the rest of the light from the origonal post.