Hacking a ridiculously cheap laser.

I bought a couple of really cheap lasers off of eBay for a project I wanted to try at codeclub (Mission impossible style burglar detector using LDRs and lasers). They were about £1.50 each from China. Like this one but cheaper.

They were not easy to use in the chassis they came in, having a momentary push button switch, and eating batteries, so I set about taking one apart.

The chassis needed a bit of hacksaw work to split, and then the controlling chip and laser came out as one. I jammed on the switch with a cable tie, and taped the +ve wire to the body with insulating tape. The spring on the chip is the -ve:

Not quite sure of the power requirements but I think I would power it through a ULN2003 and an external battery supply if I was to include it in a project. Claims to be 1mW with 3V input. My multimeter read 25mA being supplied from the arduino 3.3V pin.

Not sure what project to include it in.