Kottle Electric Eraser Kit, Automatic Portable Rubber Pencil Electric Eraser with 10pcs Eraser Refills,Battery Operated Eraser, require 2 AAA batteries (not included) (Blue) Long Lasting Use: Good quality and comes with 10 replacement refills. The eraser length 25mm, easy to remove and replace. Easy Operation: Has a simple push button for control, and a light touch are all required to remove marks. Power Battery: Battery operated eraser, requires 2 AAA batteries (not included). White Eraser Refills: Soft white eraser does not tear up paper, don't leave any traces or marks behind. Multi-purpose: Perfect for artists, animators, draftsman and architects. also, suitable to be office supply and school.