Includes a medium tier (6 7/8" wide x 5" tall) and a large tier (8 5/16" wide x 6" tall) high) . If required, a metal bracket is included to attach the cover to the electrical box, whether the box is mounted vertically or horizontally. I just cut a hole in the wall so I didn't need a bracket and just used the wall anchors that came with my new Honeywell WiFi RTH9580WF Smart Thermostat. The screws go through the base of the new thermostat and through the cover to hold everything in place. The base of the new center plate hid the mark of my 17 year old Trane thermostat (painted a few years ago) as it was vertical instead of horizontal like new. Fiction! I didn't let my eyes wander, nor my wife's request for the room to be repainted! And yes, I needed the help of my oven repair company to connect wire C (common or 5th wire) from my new thermostat to my 17 year old Goodman GMPN100-4 REV B oven to get my new thermostat wifi since the old one was 24 The Trane thermostat only used four wires and didn't need the C wire. This prompted another web search to find answers to this question. There is nothing easier.