WIKA TI.80 Stainless Steel 304  Solar Digital Thermometer, -50/150 Degrees C, 4" Stem, 1/2" NPT Connection, Center Back Mount Solar-powered digital thermometer for monitoring temperature in biotechnical and chemical processing, composting, quality control, and power generation applications Measures temperature from -50 to +300 degrees F or -50 to +150 degrees C with an accuracy of + or - 1% the scale Back-mounted, stainless-steel stem of varied length has a thermistor sensor powered by a 3V solar cell in the tip for taking measurements Provides temperature updates every 15 seconds for monitoring Powered by a 3V solar cell that operates on 35 lux of light