Material: Made of premium quality foam material and high density felt bottom, non-toxic,only the back side with high density felt bottom is magnetic.^ Designed in a bone shape 7 x 4 x 2cm (2.76 x 1.57 x 0.79 inch), the eraser features small, lightweight and cute, suitable for children and adults.^ A good assistant with strong absorb-ability, they are not just erasers, but also can be used as magnets on whiteboard or any other magnetic surface, a handy necessary for classroom, school, home, office meeting.^ To clean the whiteboard easily and effectively, just swipe the eraser with a little pressure to clean your whiteboard.^ Package Include: 40 pieces magnetic whiteboard erasers in 4 colors (Red, Yellow, Blue, Green), 10 pieces for each color. ^