Infrared proximity sensor made by Sharp. Part # GP2Y0A21YK has an analog output that varies from 3.1V at 10cm to 0.4V at 80cm. The sensor has a Japanese Solderless Terminal (JST) Connector. We recommend soldering wires directly to the back of the module and installing the header of your preference.
If you need other reading ranges you can check the following proximity sensors: