To use, simply connect the thin red wire to a positive supply, and the thin black wire to ground. Then tape the black thermistor bulb to whatever you want to measure – or leave it loose to measure ambient temperature. The display has a microcontroller that will read thermistor resistance and display the corresponding temperature from -30 Degree C to 70 Degree C with 1 Degree C precision on a 3-digit 0.56″ tall 7-segment display. The meter draws 3-4mA to power the microcontroller and display. This particular LED display is a nice vivid blue, which we found very readable. To mount to your enclosure, simply cut a 45.5mm 26.5mm rectangle and snap it in.