Electric Three-hole Desktop Punch drills through 10 sheets of 20 lb. paper at a time consistently without jamming. Features easy-to-use button on top. Punches 9/32" holes for easy page turning. Adjustable paper guide built into base. Large chip holder in base gives you plenty of disposal space. Punch includes AC adapter or use with size AA batteries (sold separately). Battery use provides enough power to operate it for a year of average use.