The Siemens 536-753A S1K RM TEMP SNSR,BEIGE,20/120F
This room sensor provides an accurate temperature input signal to any controller that accepts a 4 to 20 mA signal. The sensor has a temperature range of 20 to 120 degrees Fahrenheit (-7 to 49 degrees Celsius), an output signal of 4 to 20 milliAmps and a platinum reference resistance at 32 degrees Fahrenheit (zero degrees Celsius). This sensor is desert beige.

