Hi, all friend Here comes Joyetech eVic VTC Dual 75W or 150W Mod. It support upgradeable firmware. I think you all will like it. Joyetech eVic VTC Dual 75W or 150W Mod Powered by One or Two Cell Support VW/VT/Bypass/TCR Mode http://www.sourcemore.com/catalogsearch/result/?q=JOD002900 Short description: eVic VTC Dual features the replaceable back cover for alternatively using one or two cells as you prefer where maximum output can be reached to 75W and 150W respectively. eVic VTC Dual applies two sets of battery protection circuit system, realizing overall battery protection of over-charging,over-current and over-discharging, which makes it more safe and reliable. 1. One cell support 75W output 2. Two cells support 150W output 3. RTC display 4. Onboard reverse polarity protection 5. Dual circuit protection 6. Support upgradeable firmware 7. Stainless thread with spring connector 8. Large OLED screen display 9. Support VW/VT/Bypass/TCR mode 10. Charge via USB cable If you have any other question, just feel free to contact us.