It can be powered by Smart Phons, Tablets or Portable USB power source such as Power Bank. Powered by Miro USB Pin can be used as a value-added Gadget on the move... Maximum noise: 25.8dB... Adopts high standard aircraft motor, Load torque: 0.02 (N.M), Locked-rotor current: ⥠0.8A, Stalling torque: 0.14 (N.M). It means you can take it with you just about everywhere you go.