The ipv D2 takes one single 18650.The wattage output is 7w-75w and the Output voltage is 3.6v-7v (under power mode).The output joules are 10j-50j and the output voltage is 1.0v-7.0v (under joule mode).Input voltage is 3.2v-4.5v.Output current is 1.0A-25.0A and the Input current is 1.3A-30.0A.Standard resistance is 0.2ohms-3.0ohms and the Joules mode resistance is 0.05ohms-0.3ohms.Temp Limit centigrade is 100 degrees c-300 degrees c.Temp limit Fahrenheit is 212f-572f.And the chip is a Yihi SX130H.In the box you get your device,a user manual and a micro usb charging cable.There are several safety features on the ipv d2,low voltage protection,low resistance protection,High input voltage warning,output short circuit protection,reverse battery protection and temperature overheat protection.Typical 5 clicks to turn the device on and the rest is very self explanatory.Overall I've been really impressed with this device,very well built,battery sled is neat and clean.Spring loaded 510 and everything I've put on this has sat flush.Proper battery venting and there is a charging port for external charging but I Do not advocate doing this.Charge your batteries in a separate charger like a nitecore for example.I also forgot to mention that is also comes with a nice silicone sleeve.I will give this device a 5 out of 5 rating.Top notch and I am impressed with it,I don't really mess with temp control but this device has got me wanting to give it another shot.Feels good in the hand and is a pleasure to vape on.This was sent to me from GearBest for review,and please go visit their subforum on the main page of Vapor Talk.Thanks Guys!