The REO Variable Voltage (VV) Grand is a personal vaporizer milled out of block aluminum. The benefit is a nearly indestructible unit that can take a beating. This particular mod also carries a Variable Voltage chip made by NotCigs (maker of the Buzz Pro), giving you the ability to adjust the voltage that best fits your needs between 3.5 volts and 5.5 volts. The chip also has a 15 watt maximum power output, wheel adjustable voltage dial, reverse battery protection, over current protection and over temperature protection. It carries a 6ml bottle on board (and comes with one extra bottle) that holds your e-juice, and runs on two AW IMR 18350 3.7 volt batteries . Some new features: Rounded back side for more comfort, button on the side of the mod instead of the top, an on/off switch in the cover right below the VV dial, and a deeper reservoir/catch cup. Size (including catch cup): Height: 4 1/4" Width: 1-11/16" Depth: 15/16"