Thing is made out of a dollar tree laser and flashlight. Both need to be disasembled ans soldered to make it work. Battery is the three triple a holder from the flashlight, I soldered wires on the contacts. Also it doesn't hold to the gun super well with friction. Epoxy or double sided tape should really help. I used a single side sticky foam and that worked but might not hold up for the long haul. Switches were sacraficed from some cheap speakers but any with the right dimensions should do.
Print files in any way that makes sense for you and how you like to print. Strength should not be an issue except where the nuts are held in place, do not over tighten them