This is a small flash light to use when using the telescope. It uses 2 red LEDs. You will need the following items
4 M3x20 bolts
1 M3x6 bolt, choose the smallest head you can find
2 red LEDs
1 miniature switch
a small spring for the negative terminal
1 battery type 18650.
I used hot glue to keep the diodes and the switch in place.