The istick 100w is a dual 18650 device.The batteries seem to be running in parallel but I could be wrong,both positives up and both negatives down.You can choose between voltage mode or wattage mode.5w-100w or 2v-10v.Typical 5 clicks on the fire button to turn it on and off.Wattage and voltage adjustments are the same as most devices + for up - for down.You can change the screen display to accommodate left and right handed users.Sufficiant battery venting and the battery door has some strong magnets to hold it on.It does have a USB charging port,but honestly I advise against charging this way.Better safe than sorry.Atomizer protection,Atomizer short-circuit protection,Low voltage protection and Temperature alert.Floating 510 (appears to be copper) but I'm not positive.So overall it's not a bad device at all.100w is more than enough power for all vapers.Feels nice in the hand and no rattle at all.There is one Con and it's a big one (for me at least).Every atomizer that I have put on this device WILL NOT SIT FLUSH.I honestly can not figure out why.And the crazy thing is it's about a playing cards width in gap,frankly it drives me nutts.If attys not sitting flush doesn't bother you then this is worth buying.But I know most people on this forum would agree it is no Bueno.A deal breaker for most seasoned vapers.Overall I'd give this device a 8 out of 10.If atomizers sat flush it would be a 10 out of 10 easy.This was sent to me from GearBest.com for the purposes of this review.Thanks guys!