The present invention relates to a golf club head provided with a face and a body. The pipe contains a flow of bleed air and includes a plurality of inlets and an outlet. The system may be used in fields such as manufacturing integrated circuits, and low- and very-low-frequency geophones, and other low- and very-low-frequency acoustic detectors. Since for the different light sources the same color shift function can be used, a determination of individual operational driving currents such that the light sources of the group emit light having substantially the same color can be simplified. Multi-reservoir pressure modulator and pressure controller systems can optionally be used in conjunction with electrokinetic or other fluid transport mechanisms.