The weiss patented* digital vari-angle thermometer maintains the strict requirements for thermometers in hydronic applications in that theyre self-powered and within 1 percent accuracy. This reliable Series of digital thermometers offers the added feature of stem assemblies for direct replacement of mercury-in-glass types where environmental concerns exist. Whether on new installations or replacements, our vari-angle digital thermometers include the same level of quality that the industry associates with the vari-angle trademark and all weiss products. made in United States. Manufactured by Weiss Instruments.