Size is 24 inches X 36 inches.
There's nothing like them on the market.
The chalkboard surface is the highest quality porcelain on steel. The panel construction is composed entirely of non-porous materials to give the board extended outdoor life - free from excessive warping and moisture absorption that you would experience when exposing a standard chalkboard to the elements.
Anodized aluminum frame is impervious to weather.
Use with a regular chalk or markers sold by billyBoards