This is a retired product, but fear not as there is a newer, better version available: SEN-12728
Description: Infrared proximity sensor made by Sharp. Part # GP2D120XJ00F has an analog output that varies from 3.1V at 3cm to 0.3V at 30cm with a supply voltage between 4.5 and 5.5VDC. The sensor has a Japanese Solderless Terminal (JST) Connector. We recommend purchasing the related pigtail below or soldering wires directly to the back of the module.