A mechanical coupling device is provided for temporarily interconnecting a gem or a crystal to be used for acupressure treatment to a vibration generating device. The valve includes a check valve, a carrier film having adhesive on a surface thereof, and a plastic stand-off with projecting protrusions. An actuating member can press the fixed brake disc and the rotating brake disc against each other and against a stop surface on the fixed body to apply the brake. A variable inductor is connected with the sourcethe emitter of the transistor. A metal layer separated from a pixel electrode is formed without increasing the number of masks, thereby simplifying the pixel electrode and obtaining etching characteristics of a gate electrode. Each element comprises two or more layers of transducer material.