https://www.youtube.com/watch?v=xZ8vv-BwVEQ

Yep, this is another l.e.d. keychain. I think I'm a bit obsessed by this sort of things. This design is similar to other ones that can be found on thingiverse, but the "button" part in this case must be printed with flexible filament. I also suggest to print all parts at least at 0.12 res, for better results

To assemble, you will need a 5 mm led, a 3volt CR 2032 battery, a little piece of electrical tape, the button part and one of the 2 body parts (there is a version with a hole to attach a ring and a version I made for paracord string).

Just note that in order to make it working you have to stick a piece of tape on one side of the battery to avoid it making contact with the legs of the led. Bend cathode (shorter leg) in "O" shape and put the led in its place and then insert the battery. Negative pole must go facing down. Once you have inserted the LED and the battery in the main body, you should be able to slip the anode through the tiny hole on the base of the button part, bend it and then push all down to make the two parts fit together, the most tricky part. This may help https://www.youtube.com/watch?v=XPqRqoqn_vM&t=40s if you have any trouble, let me know in the comments