This works great! I am using it to monitor the temp in a small server closet to make sure the temp doesn't skyrocket and damage the servers. I love the fact that it is AC powered as I didn't want to have to keep checking on a device that needed batteries changed. The alarm is the right volume for my setting (a hallway on a nursing floor in a hospital) when it goes off everyone can hear it up and down the hallway. The one thing that is not listed in the description is that it has the ability to set the alarm to go off immediately when the temp limit is reached or you can have an hour delay with the time resetting if the temp falls below the set limit. This helps with small fluctuations in temp that may reach your trip point but not really be a problem.