Be careful. Aluminum is a conductor of electricity. Make sure that you don't complete a circuit when you install the batteries and close the lid.

Sorry, as a former safety inspector, I had to say that.

Surefire makes a CR123 battery carrier. I'm sure that there are others as well.

I'm not knocking the K&M matchcase at all - I own two of them. As far as I'm concerned, they're the best match cases available.