PHOTO AMP 1 CH 2NPN SPDT TIMER, AMPLIFIER FOR THROUGH BEAM SENSORS, RANGE UP TO: 50000MM, ADJUSTABLE SENSITIVITY, DISGNOSTIC FUNCTIONS, ALIGNMENT HELP, POWER SUPPLY : 24 VAC/DC, SPDT RELAY + NPN OUTPUT, 11 POLE PLUG CONNECTION, UL508, UL325, CSA, ALARM OU