Worried my old thermostat wasn't working so I purchased this unit. Model numbers were almost identical and checked the wiring. Took about 15 minutes to switch them. However, the problem turned out to be a blown capacitor that was in the AC unit for 18 years.Moral of the story, call someone in to check your AC. FYI, learned a capacitor only last around 16 - 20 years. The technician who fixed everything stated my install of the thermostat was done perfectly.This can be auto changeover or pretty much a base thermostat and has some flexibility with programming. Not seven day but 5-2 or 5-1-1. Lots of capabilities for a low end control. I got a few of them because they’re simple to operate. Used them many times over the years.Once mounted, it is difficult to remove from the base plate. I changed the #6 mounting screws to #8 with more robust plastic wall plugs.Youtube helped understand the instructions which were rather vague.Accurate temperature control and simple installation.I love this thermostat. We moved into a four-year-old house and immediately change it to this thermostat which is what we had in our old house. I love it. The ease of programming is great.Great device, just what I'm looking for.Happy with productIt was a cheap replacement compared to a really expensive new oneBought to replace our manual thermostat. Wiring was a bit tricky bc I had to figure out what I had in my condo (an electric heat pump / ac unit in one). After that, programming is easy and works great!Works great, might get another for my houseEasy to install. Temperature can be set to .5 degree.keep it up!