The Digital Sensor TTP223B Module Capacitive Touch Switch is based on a touch-sensing IC (TTP223B) capacitive touch switch module. Allows you to remove the worry of conventional push-type keys. Digital Capacitive Touch Switch Module is based on TTP223B. Normally, it outputs low and keeps at low power state. When a touch is sensed on the circular marked region, it outputs high and switches to the quick response state. When not being touched for 12 seconds, it switches to low power state again. If the module is mounted in the surfaces of non-metallic materials such as plastic, glass, acrylic, you can make the keys hidden in the walls and desks. In addition to the thin paper ( non-metallic ) covering the surface of the module, as long as the correct location of the touch, you can make hidden in the walls, desktops and other parts of buttons.