Different membrane buttons and traditional silicone keys work, it is covered with conductive metal film covered with metal points, when the button down movement, the button below the conductive adhesive material or metal shrapnel just fall on the metal point When the mask layer is not pressed, the isolation layer isolates the upper and lower lines. When the mask layer is pressed, the upper line is pressed together and coincides with the lower line to make the line conductive. Connect externally to the instrument (set by the customer) to achieve its corresponding function.