I really love my Tekk mod. No batteries to change out and it lasts 3 days on a charge. Great horn button. Consistent vape with great vapor. It charges with a usb cord. It contains 2 18650 batteries and is regulated to 5 volts. It has a 5 volt in for usb charging, and a 5 volt out to power other devices. The kit comes with all the adapters so I also use it to charge my Droid when I'm out. It will also power a passthrough. I've plugged an ego passthrough into it for a passenger in my car while I was using my Tekk. I really love it with the regular 306 atomizers or 306 cartomizers.
I know COV sells them (although I had a modder build mine). When you realize that you don't need to buy extra batteries or a separate charger, the price is really great. The batteries should last as long as cell phone batteries so I'm expecting to get a lot of life out of this.
I could leave the house for the weekend with just my Tekk, a spare atomizer, and some
juice and vape heartily until my return home. I've had this for over 2 months now and I'm still loving it.