g pen hydout 510 cartridge batteryBuild & Pocket Feel G Pen Hydout 510 Cartridge Battery keeps a tidy footprint that rides well in a pocket or pouch. The magnetic cap protects the mouthpiece and gives the device a clean, low key look. Edges are smooth, so it slips in and out without catching. The LED readout is easy to read at a glance. Power Settings & Preheat Pick a preset voltage and the device does the rest. Lower settings suit light oils and easy sips, higher settings add punch