Digital Thermometer, DC 4-28V -50 to +125 Degree Celsius Indoor Outdoor Thermometer Dual Display LCD Temperature Gauge Sensor with 2 NTC Waterproof Probes for Aquarium Vehicle Fish Tank Refrigerator

The media could not be loaded.  One good thing about this unit is that it has a wide operating voltage and relatively low current consumption (10-12mA). Unfortunately, it does not use type-K thermocouples, and the range is a bit limited. Another thing is that the unit has no buttons and appears to be stuck in either C or F mode (mine came in the C flavor). Perhaps including circuitry to switch was non-trivial? I was able to measure ice water in a glass to .3 degrees C, which is either slight inaccuracy, or true temperature (I live in a hot city). My residence is located 4008 ft. above sea level, so that is why water boils at about 96 degrees C in the video, it's not the meter's fault. Overall, even though this equipment is limited, I do feel you get good value and everything worked as promised, so I can recommend it!

The media could not be loaded.  With this one I can measure both my fridge and refrigerator at the same time! I like that it can be powered by a 9v battery and the probes are long enough for my application.This came preassembled, I just needed to power it and place the probes where I needed.It looks sturdy enough for my application and works flawlessly.After plugging it to the battery, it immediately displayed the two measurements. Both measurements seem accurate enough as the difference isn’t really significant.

I wanted a two-sensor unit that reads in degrees F, I could slip each sensor against the metal of an 80 gallon hot water tank so to read/verify approx. temps by each heating electrode, can see bottom electrode temp as bottom number, top electrode's temp as top number, plus this unit's bright light is easy to see from a distance about 8 feet. Works great. Another plus is that I could connect the +/- wires directly to adjacent solar charge controller's VDC output and the unit can run on solar.

Test out 4 X 3.75 vdc batteries only worked for two days. Replace with power supply working fine. It show indoor and outdoor temp. Will buy one more unit after test out 5 days.