Die-Cut Magnetic Calendar Set (Superhero Theme) Add pizazz to your homeschool or traditional classroom with this Superhero-themed die-cut Calendar set. Great for whiteboards, steel lockers, refrigerators, etc.  Use with write-on/wipe-off markers or chalk pens. Each set includes 47 die-cut pieces that easily punch out from a 12″ x 17″ sheet.