Akiles CombMac-EX24 Binding Machine Electric Built- In Comb Opener High Volume Punching Capacity: Up to 25 sheets 20lbs paper (Letter Size). Depth Margin Control: Provides the correct punch margin depth for each comb size, while maximizing document tear resistance. Open Punching Throat: For punching of longer documents. Open Punching Throat: For punching of longer documents. Side Margin Control: Provides evenly centered punch for all document sizes.