With the Akiles DuoMac 541 you can bind documents with both 5:1 pitch spiral coil and 4:1 pitch spiral coil. The DuoMac 541 is the only combination machine of its kind. The unique design of the 541 includes a the ability to punch both a 5:1 pitch hole pattern for spiral coil binding and a 4:1 pitch hole pattern for spiral coil binding. This gives you the ability to choose the look and feel of your coil bound books and presentations. Five to One pitch coil (5 holes per inch) has a more tightly wound look than the more common 4:1 pitch coil (4 holes per inch). Normally, you would have to use two different binding machines to do the same tasks as the DuoMac 541. This meas that the DuoMac 541 can save you space, time and money.