Winters 91TSD Industrial Solar Digital Thermometer, 3-1/2" Stem The Winters 91TSD Industrial Solar Digital Thermometer, 3-1/2" Stem is a versatile instrument used in many industrial applications. The display on the thermometer is a switchable dual range scale (F/C) and offers a +/-1% accuracy. The thermometer is solar powered with a battery backup. The Industrial 9IT Solar Digital Thermometer is made of high impact ABS plastic housing, with a 3 1/2"(90mm) or 6" (150mm) stem length and a 3/4" NPT brass thermowell standard. The instrument is mercury-free and environmentally friendly. Winters 91TSD Industrial Solar Digital Thermometer, 3-1/2" Stem Specifications: Size / Scale: 2.55 x 4.67 (63.75mm x 116.75mm) sensing display readout Angle: High impact ABS plastic housing with aluminum movable parts Temperature Range: Switchable between -50F to 320F (-45C to 160C) 6 second response with battery back up Stem length: 3-1/2" (90mm) or 6" (150mm) Ambient Temperature: 14F to 150F (-10C t