Variable Voltage Mods
Any PV, APV, or Mod that allows the user control over the voltage output of their device. Generally recognized as superior to regular PVs that have a static voltage output that cannot be changed.
Vapers often buy a VV mod without actually requiring one as they stick to the same tank and coil combination which just requires a single voltage. If the vaper is using various tanks and atomizers with different resistance coils then a VV mod can be very useful.
VV mods generally range from 3.0v to 11.0v. A standard ego battery runs at 3.7v.