The Coralife Digital Thermometer is my first digital thermometer. I wanted something small, easy to read, and reasonably priced (I paid under $10).
The unit is attached by suction cup. One button to turn on/off and toggle readings. Temp readings can be switched from Fehr/Cel.
The cord is long allowing the probe to be easily hidden from view. Battery is included
After 2 months of use, the temp readings suddenly were 5+ degrees off and the display randomly blinked. I removed the battery which fixed the problem until is started again a week later.
The Coralife themo is a good purchase if you're looking for a digital thermometer, but it's reliability is questionable. The only thing I expect of a thermometer is to be accurrate and precise. That said, I keep my old analogue themometers close by.