Swingline Optima 20-Sheet Capacity Electric Three-Hole Punch, SilverModern design is compact to save desktop space and easily fit in your hand. Electric or battery operation. Alignment indicators for precise three-hole punching. Transparent, hinged chip drawer. Oversized activation button offers quick, efficient operation. Automatic reverse feature releases jammed paper. Operates on six AA batteries (sold separately) or AC adapter (included). Sheet Capacity: 20; Operating Method: Electric/Battery-Operated; Number of Holes: 3; Hole Diameter: 9/32".