I made my own when I saw the prices of some of the commercial ones. Fairly cheap, a couple of lasers, some Line-loc flexible tubing, a box, a little voltage regulator to drop the incoming voltage to match the lasers, and a battery. I added a port for a nine volt battery holder so it didn't have to be taken apart to change the battery. I'm thinking of upgrading the battery to a 12 volt rechargeable...
Steve