A flow regulator for a water pump, comprising a valve body, a piston block, a spring, a connecting pipe, and a rod. Jet flow velocity Ue at the edge and a jet-blowout-outlet-to-edge distance d are detected by the sensors. 7% with respect to an orbital frequency at the charged-particles’ extraction portion, during a time of injection to extraction of the particles. The tremolo mechanism also includes a plurality of tension rollers for providing rotational tension to said guitar strings. The outer wall extends distally from the base and around the coil and also defines a distal end.