This stellar collection of Pro Vaporizers run off 400mAh batteries, have an extended 12s preheat function for ludicrous power, and are easily charged via a Type-C cable! The Wulf Pro is souped up with incrementally adjustable voltage levels all the way from 2.0 - 4.0v. Making the Wulf Pro truly special, is the fact it has an actual OLED display built in! This is not something you often see in pen vaporizers, easily check your battery and voltage level with an incredibly vivid easy to read screen.