Siemens 540-520B ROOM TEMPERATURE SENSOR, FLUSH MOUNT, 10 K OHM, 55-95 DEG F, WHITESiemens 540 520B Room Temperature Sensor, Flush Mount, 10 K ohm, 55 95 Deg F, WhiteThe Flush Mount Room Temperature Sensor is a 10K ohm self contained, non intrusive and tamper resistant unit. The sensor connects to the RJ 11 port of the controller via a pre terminated cable. This unit has a white plastic cover. Additional Information Measuring range, temperature1335 C Sensing element10K ohm NTC Thermistor Operating voltagePowered from TEC controller