I got my nautilus from www.vaporsabre.com its a 901 you can use at 6v or 3.7 it takes the cr2 3v or 18500 at 3.7 I vape at 6v It goes for 69.99 and its a pretty good deal I been useing it since 9am and i can say it vapes like a 6v very good vapor and troat hit i like how it feels in my hand its not a bulky mod like some of my 6v mods it looks better in person then it does on the web site it looks cool on the web site but better when u get it the button is nice you can puy in your pocket with out it going off it just a well build mod most e-cigs this good cost 100$ so you cant go wrong.