Our new USB pen battery is discreet and super sleek! Just unscrew the included USB charger and attach it to a cartridge. No need to warm up or press any buttons, just take a drag and exhale. The battery is draw activated and take a little over an hour to completely charge. Comes packaged in a childproof carrying tube. Comes in 2 colors - White with a Resynate logo or Discreet Black with no logo.