Product review (5 stars): Thermostat Control for Brewing
Very easy to install - takes only about a minute to set it up.  When measuring with a separate, digital thermometer, I concluded the unit is accurate to within 2 degrees Fahrenheit...or perhaps my digital thermometer is slightly off.  Regardless, it works great - definitely recommend it for converting old fridges into a kegerator or for use in fermenting homebrew at a specific temp.