Danfoss proportional thermostat 24v for Two and Four pipe system wapplications & features these transmitters/controllers functions effectively as for temperature monitoring & controlling within liquid and steam pipehigh performance digital temperature sensor, Ensure accurate measurementfast response and good long over voltage term stabilitymultiple, And reverse digital technology, Outputs selection applied high reliability, Polarity protection and interference capabilityoptional relay for alarm or on/off controllight and advanced easy installationwide, Design housing working temperature rangemmi can set parameters and calibrate output, So that the product becomes a stand alonehigh protection rate up to ip65specifications sensor digital temperature sensorrange see modelsoutput 4~20ma 3 wires, 0~10vdc, Rs485 / modbusstorage temperature, 40~85 crelay 1 spdt, 1a/30vdc or 0. 5a/125vacaccuracy power 15~28vac/15~36vdcwork temperature, 40~85 c, 0~95%rh non condensing storage temperature, 40~85 chousing abs, Ss probe, Ss wellprotection ip65agency approval ceoptional accuracy 0. 25 c @, 20 ~105 c add h after part numbers