I purchased two of these thermometers and put both of them into the spa. One of the thermometers indicated 5 degrees higher than the other. After a few weeks of use, the more accurate thermometer developed inside condensation and it became very difficult to read the temperature. I will try to return both of them.

I attached this thermometer inside my pool via the small rope/string that is included with it. Within a few months, the rope deteriorated and broke in the middle. I allowed the thermometer to just float in the pool, but then found the glass broken one day. I have vacuumed the bottom and hope I got all the glass. I was told by Leslie's customer service that there is no mercury in this thermometer, just oil, so that is a relief. The string was in the sun part of the day, so maybe that contributed to the deterioration, but I would recommend you look for a sturdier product.

We've had one of these for over 2 years. We weren't sure of it's accuracy, really, but it was in the ballpark. One hot day, I laid it on the side of the pool to see how that would affect the temperature, then put it in the pool, and it broke the glass! I just wanted to warn others not to do what I did!!!

the thermometer broke away from it's case within a month or so of purchase. String used to tie thermometer to pool ladder rotted away within less than a month. Unusable now.