A laser pointer that used LR44 batteries.
3 AAA batteries.
at least 4 1/2 inches of 1/2 CPVC pipe
6 inches of 14 gauge wire
Needle nose pliers
Then bend an "S" on the end of the 6 inches of 14 gauge wire. Once again, 14 gauge was critical, as 12 would not fit, and 16 was too loose. I am remodeling my house, so I used a piece of ground wire. Magnet wire would work well, but don't forget to sand off the insulation where it touches the battery terminal, and where it touches the inside of the case of the pointer.
Then, put a battery with the bump end (+) touching the "S" of the wire, and slide this into the pipe.
With the "S" flush with the end of the pipe, there should be 1 (one) inch of the Negative side of the battery protruding, and about 1/2 (half) inch of wire.