As other reviewers said, the temperature reading is off by at least 5-7 degrees. I have 3 thermometers in my aquarium (1 in the main display, 1 in the sump and 1 in the overflow box) all from different manufactures and they all read around 78 degrees give or take 0.5 degrees. This one tells me my aquarium water fluctuates from 71 to 78 degrees every few seconds! This is actually an outdoor/indoor weather thermometer and a bad one at best. First, the probe is clearly not meant for aquarium use as it uses a cheap rubber material coating that will quickly corrode away in water. Second, the outdoor temperature from the probe in air is about 3-5 degrees different from the indoor temperature reading of the same air! The cheap coating on the probe obviously interferes with its functionality. I'm returning it ASAP for a refund. Waste of money!

I think this thermometer is great. My landlord prefers that I use the wood stove versus the oil burner, but it can get pretty cold at night in the winter when the fire has died. I have the alarm on this thermometer set to go off when the temperature drops to a certain point, so I can get up and start another fire.

Several months following purchase, this thermometer began recording temperatures that were 4-5 degrees higher than the actual water temperature. Communications posted at the company's website asking for repair or replacement were ignored.

This unit is not even close to being accurate. it's 2.5 degrees off. I liked the design. But now wish I had not purchased it. Maybe it will last a fvew months.

works great