well you may be asking yourself what is the RTV BAB well in short it a Big Ass Battery

THE BAB MOD is a high-tech variable voltage electronic cigarette that lets you adjust the voltage between 3.0V and 6.0V adjustable in 0.1v increments, with simple operations. It gives you the freedom to control the vapor volume by yourself anytime. 

It is made of metal alloy with a black painted finish. It comes with a standard 510 connector, so we include a FREE 510-eGo adapter adapter to make you use eGo/eGo-T/eGo-C atomizers with this Variable Voltage MOD.

Unlike other Variable Voltage MODs, the BAB MOD body consists of two separate parts: mod control unit and mod battery tube. This starter kits comes with the BAB variable voltage MOD battery tube(18650) and a 2200mAh 18650 rechargeable Li-Ion Battery

On the BAB control unit, there are 3 buttons:

Main button(largest one): Press to active LCD and show puffs and battery capacity. 

2  Voltage adjustment buttons: Use the + and - buttons to adjust the voltage in 0.1v steps. Once 6.0 is reached the voltage will step back to 3.0 if you push the + button again, also, once 3.0 is reached the voltage will back to 6.0 if you push the - button.

The LCD screen can displays the voltage when you use the + - button to adjust the voltage. 

Be careful not to damage atomizers/cartomizers. Driving them with too much power for too long or running them dry can burn them out. We recommend you starting with a low voltage setting and working your way up until you find the right setting for your atomizer/cartomizer.

This MOD KIT is a MUST HAVE for any serious Vapor Enthusiast you can read more about it and ORDER one HERE