Thermometers feature a 1/2 npt threaded connection and polycarbonate lens. External adjustment allows for simple field calibration. For correct temperature reading, stem must be immersed at least 50mm 2 in liquids and 100mm in gases 4. Each thermometer features stainless steel case and stem and is individually packaged with a multi-language english, french, german, italian, portuguese and spanish statement of test and calibration. B61310-9400 and b61310-9500 feature a glass lens.