Desert Song Electric Pencil Sharpener, Powered by AC Adapter (includes), USB or Batteries (not includes), Quiet Pencil Sharpener for Classroom or Office, Works for Colored Pencils_Green Features heavy-duty motor, helical steel blades and auto-stop mechanism for the ideal tip It takes only 5 ~ 7 seconds per sharpening and very portable Choose between 3 levels: blunt, medium or sharp Power by three kinds of power supply: AC power supply & computer USB power supply & batteries BUY CONFIDENTLY with our 100% Money Back Guarantee: No questions asked and hassle free.