I bought the 20 x 12” warming plate to use for Thanksgiving because I want to simplify and am tired of bothering with Sterno pots. I liked it so much, that I bought another one to have two for Thanksgiving. I tested both of the warming plates beforehand to avoid discovering anything unexpected on Thanksgiving day. Here is what I learned:The seller advertises these as 20 x 12”. That is the size of the heated portion of the surface—the actual dimensions of the flat surface are about 1” larger all the way around, plus the size of the handles.The surface is just like those black glass cooktops—sleek and good-looking.There is an on/off toggle switch on the side of each warming plate—you CANNOT adjust the temperature.To test the temperature, I put identical UNcovered Corning ware casserole dishes on each warming plate, filled with cool water. It took a LONG time (e.g. an hour) for the water inside the casserole dishes to heat up. With lids on, the contents heat up MUCH faster. TIP: Heat the food first, then use these warming plates to keep it warm. Whenever possible, use lids on the food.After allowing the covered casserole dishes to heat on both warming plates for an hour, the temperature of the water in both was 170 degrees—much less than the seller’s stated “up to” 203 degrees—but still plenty warm enough for food without drying it out. When I removed the lids, the temperature quickly dropped to 140 degrees. A reminder to keep the lid ON the food whenever possible to retain heat.The cords are only 40”, so you may need an extension cord. Since these have 3 prongs, you may need a special extension cord or power strip that handles that. Regular lamp extension cords don’t work because they are for 2 prong cords.Overall, these are sleek, good looking, and work well. Be prepared to buy a power strip or 3 prong extension cord (with a multi-end if you are using more than one of these warming plates). Keep your foods covered to heat and retain heat more effectively.I am really happy with these and do recommend them.I write honest reviews to help others make informed purchases because I read reviews myself and appreciate how helpful they can be. I hope that my review helped you!