Siemens 533-377-4 DUCT POINT TEMPERATURE SENSOR, PLATINUM, 30 TO 250 DEG F, 4-INCHSiemens 533 377 4 Duct Point Temperature Sensor, Platinum, 30 to 250 Deg F, 4 InchDuct point temperature sensor (single point, rigid) with a 100 ohm platinum RTD sensing element. Temperature range is 30 to 250 degrees Fahrenheit ( 1 to 121 degrees Celsius). This unit has a 4 inch (10 cm) probe. Additional Information Measuring range, temperature 1121 C Sensing element100 ohm Platinum RTD Operating voltage18 to 36Vdc or 24Vac 20 % Analog outputs4 to 20