Seeing as the kits only come with 1 battery and that won't work out well I'd suggest buying a 510 starter kit from any of the reputable companies around here. He'd get 2
batteries, charger, 2 atomizers, 5 carts in most standard starter kits.
Barring that, I can't be 100% sure but it does appear to be an rn4081 and I KNOW there are better prices on the parts than that site is advertising. The carts appear to be the same as the 4081 at least, so the cartridges are refillable. There's a little plastic white thing inside that you can pop out with a paperclip to refill em.
Edit: The
threads are opposite my 4081... WTF. hmm...I'll try hitting the web to see if I can track down some better intel.
Edit: Nothing...just one reference back to here. Either way, my advice is definitely to grab a 510. It'll perform better, doesn't just come with 1 batt, and overall the pricing is just plain better.