This marker board comes with 8 commercially available, standard sizes built-in. It is ideal for layout of classrooms for elementary schools, high schools and colleges or universities. The sizes range from 3 feet to 16 feet. The Revit family is fully flexible using built-in parameters, so you can make any custom sizes you prefer.
(Marker boards are also known as whiteboards or dry erase boards. They replaced chalk boards in common use in the past.)