Electric binding system has all the convenience features you need to bind fast and easy. Paper centering system combined with vertical feed aligns paper for more accurate punching. Document separator divides your stack of sheets into the right thickness for flawless punching. One-touch electric punching is easy and productive. Rotary dial provides precise control of comb opening and closing. Binding machine punches up to 25 sheets of 20 lb., letter-size paper and binds up to 500 sheets.