Case : black steel (chromed steel, stainless steel) Ring : black steel (chromed steel, stainless steel) Window : glass Hot water Thermometer Type 212Applications Used in HVAC industry for hot water lines , boilers and hydraulic ,etc. Case : black steel (chromed steel, stainless steel) Ring : black steel (chromed steel, stainless steel) Window : glass Dial and pointer: aluminum Stem: brass ( ...