If you were to use 510 cartos, I'm guessing an ego cone will work with this?
fright, it sounds like your friend has the exact batteries he needs for this mod.
Here is the product description from COV:
NEW! 5v Wow! Mod! Finally a 5v regulated tube Mod you can afford! Black finished Aluminum is light weight! Feels nice in your hand! I love Dual Coil Cartomizers at 5v! Use the 510 or even better the eGo Dual Coil Cartomizers. Or atomizers. Uses 2x LiFePo4 3.0v CR123A Batteries. Choose from AW, Tenergy or COV LiFePo4 Batteries. Get the Tenergy Charger Pack with 2 batteries and a charger for the wall or your car!
It seems to vary by vendor. I've seen those same batteries listed at some sites as 3v and others as 3.2v, but they are both the same battery.
......... Dang Nabbit will they ever stop making bigger and better things!!!!!!