The present invention relates to a work-indicating unit of a magnetic control exercise apparatus. Devices with deployed dimensions of 26 to 40 mm or more are disclosed that are compacted to extremely small dimensions of 5 mm or less, enabling percutaneous delivery of said devices without the need for surgical intervention. The modularity also allows the width of the transport vehicle to be adjusted using different widths of connectors to accommodate road conditions andor governmental regulations. The silicon layer or the silicon is dissolved into the low-melting-point metal layer by a heat treatment. Various resistance values can be set in high precision by selectively turning on or off the plurality of transistors.