A durable and accurate thermometer with a rigid connection. Separable thermowell. Rugged steel case. Bi-metallic element. Dual scale. Bottom connected. 1/2" NPT process connection. Applications: hot water lines, boilers and hydronic heating. Dial: 3-1/2" aluminum with black markings. Case: steel. Lens: glass. Ring: steel chrome plated. Stem: brass. Thermowell: brass, 1/2" NPT bottom. Recalibrator: standard. Sensing element: bi-metallic coil. Pointer: aluminum, painted black. Over range enclosure rating: +/-25 Percent of full scale value. Reset: standard. Ambient temperature: -22 degree fahrenheit to 158 degree fahrenheit. Process temperature: -22 degree fahrenheit to 250 degree fahrenheit. Accuracy: +/-2 Percent of full scale. Enclosure rating: IP50. Temperature range: 30 degree F to 250 degree F.