Switch, proximity. Sensing range: 0mm - 4mm (0.16"). Rated voltage: 12 - 24VDC. Supply voltage: 10 - 30VDC). Current: 15mA. Cylindrical. Sensor input: Capacitive. Sensor output: NPN. More info: http://www.ia.omron.com/data_pdf/data_sheet/e2k-x_dsheet_csm460.pdf Proximity sensor.