Electric Pencil Sharpener High Quality UBS & Battery Operated, Great for Office School & Kids Safety switch prevents operation when shavings tray is removed SharpStop automatically shuts motor off to prevent over sharpening Replaceable Sharpener Core Design - greatly extending the service life. [1 * replacement core included] Sharp durable SK5 steel blade & large easy-clean shavings tray with faster and stable cutting performance. Multiple Power Sources - Can be powered by either USB (wire included) or 4 AA batteries (not included).