The ASL 204 Non Adjustable Proximity Sensor with 3 Pin Connector is a no touch switch and made to interface with any ASL non proportional driver control. This single function switch has an activation range of touch to a half inch. The activation occurs when it senses a hand or another part of the body in the activation area. The 3 pin connecter plugs into any ASL driver control cable, ASL 151 Interface or the ASL 101 Single Switch Scanner. These switches are typically used for individuals with Cerebral Palsy or with anyone that has difficulty with motor control, coordination, or weakness.