TruBind 13-mm (1/2-inch) Binding Coils - COIL13 - Durable - 4:1 Pitch (4 holes/inch) - 12 Inches Long - Pre-Sized to Fit Letter-Sized Paper - Compatible with TruBind Binding Machines - 100 per Box Size: 13mm (1/2") Length : 12" Color: Black Qty: 100/box Pitch: 4:1