Battery cover design of iStick TC200W

The Eleaf iStick TC200W (buy it online: http://www.istick.org/istick-tc200w.html) comes with a flip-open battery cover, this innovative change is really easy to operate, therefore once the battery of Eleaf iStick TC200W Fireware Upgradable Box Mod run out of power, you can flip open the battery cover and lock three interchangeable 18650 cells.