A touch module switch circuit includes a universal serial bus display circuit, a touch module, a first resistor, a second resistor, a first diode, a second diode, a USB switch chip, and a USB interface. A member having a wall is obtained. The method also includes, but is not limited to, designing an improved multimode fiber optic cable which compensates for at least a portion of the chromatic dispersion and modal dispersion present in the reference multimode fiber optic cable resulting from the transmitter’s fiber-coupled spatial spectral distribution.