This Canterbury 20" x 30" Whitewashed Wall Mount Magnetic Chalkboard fits perfectly in my office. Wall mounted, it can be hung either vertically or horizontally and includes the screws and anchors.  It comes with a box of chalk and eraser with a magnetic strip on the back.  Besides a chalkboard, it can be used to display anything magnetic and more. 

The magnetic strip on the eraser separated and fell off after only two days and had not been touched during this time. Nothing some super glue can't fix but worth mentioning.