Quick view Compare Add to Cart The item has been added Siemens Siemens 536-811 : Duct Temperature Sensor, 100K Ohm Thermistor, Point Sensor, 4 inches (rigid), bracket mount Probe, -40¡F to 180¡F (-40¡C to 82¡C) MSRP: Was: Now: (Inc. Sales Tax) MSRP: $43.75 Was: Now: $16.63