Can be used to teach subjects digital time relationship and analog time Including telling time in 12-hour and 24-hour formats, which are used as an international system around the world. The board is made of plastic. Polypropylene (PP), which is strong and resistant to abrasion The erasable pen can be used to write or erase time or text. It consists of a replica watch. Not less than 5 pieces can be written on the replica watch and can be erased. Overall dimensions are 12.5 x 16 centimeters.