This is 3' wide and almost 2' tall. It's screwed in to the wall with black screws. I purposely made it wide enough to fit well over at least two studs in the walls. There are also metal strips in it, to use magnets. You can choose to have yours with or without the magnet strips.
I strongly suggest you use very soft chalk or chalk pastels on there so that it cleans off easy. Hard chalk is hard to wipe off.