Akiles Coilmac-ER 41 Plus Manual Coil Punch with Electric Coil Inserter, Special 4 x 5mm Oval Holes, Fully Disengageable Pins, Letter 4:1 pitch (0.248"), Extended Single Punching Length (13") Fully Disengageable Pins: For a completely clean & professional punching ofany paper size, all 54 pins can be independently pulled & disengaged Letter 4:1 pitch (0.248"): This revolutionary 0.248 coil pitch is specifically designed to give you 44 evenly-centered holes in an 11 sheet, which provides the most ideal hole to edge-of-sheet margins and easier coil insertion Extended Single Punching Length (13"): With open ends & continuous punch guide to easily punch documents of any length (up to 26") High Volume Punch Capacity: Suggested up to 20-sheet for 20 lbs paper, or 2.6mm (28-sheet equivalent) for hardboard, in 13" length (53 holes) Super Strength Punch Mechanism with exclusive "Precision Guiding System" Blade Set: Cast-hardened & heat-treated steel dies provide superior strength & hardness