The Renz 321600123 binding elements are professional-grade wire spines designed for high-capacity document finishing. These 16mm (5/8 inch) black wire rings are engineered for a 2:1 pitch (2 holes per inch), allowing for the secure binding of larger reports that exceed the capacity of standard 3:1 wires. Capable of holding up to 135 sheets of 80gsm paper, these A4-length elements feature 23 loops for a precise fit. The high-quality nylon-coated steel construction ensures the spine remains dimensionally stable, providing a smooth 360-degree page rotation for easy handling and professional-looking presentations that lay perfectly flat.