The electric CombBind C450E has all the convenience features you need to bind fast and easy. Exclusive "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 punching. One-touch electric punching is easy and productive. Rotary dial provides precise control of comb opening and closing. The binding machine punches up to 25 sheets of 20 lb. bond letter-size paper and binds up to 450 sheets. Maximum comb size is 2".