It had come time to replace the old thermostat installed in my home. The old one was full of dust, and highly unaccurate, as it was an old-fashioned non-digital thermostat that used mercury to run. After installing the new one, I discovered the old one was keeping my house 2 to 3 degrees warmer than I thought it was, which was probably wasting lots of energy and money. I thought installation was rather easy considering the nature of the product, however you may want to get a qualified professional to install a new thermostat. All I had to do was screw the base onto the wall, and match up the wires based on the schematic in the instruction book, then pop the main works of the thermostat onto the base. This thermostat works with electric or natural gas heat, and has a switch inside that properly sets heating cycles for what you have. It can display temperatures in farenheit or celsius. It is not a programmable thermostat, since that wasn't what I was looking for. It has a large digital display that lights up green to make it easier to see when you push a button. It stores two temperature settings in memory - what you have your heat set at, and what you have your air conditioning set at, and it will not lose those settings even if the power goes out. If you're looking to save money on heating and cooling bills, then it is necessary to have a digital thermostat like this in your home. The old kind of thermostats that use mercury are horrible at knowing what the real temperature is, so you could be running your heating or air conditioning much more than you need to.