1PAPER CAPACITY: These double ring bindings can hold up to 180 sheets of A4, 70g paper and are compatible with most 3:1 pitch and 34 hole pattern wire bundling system 2METAL INNER WIRE: The interior of the binding wire is made of excellent metal wire, which is strong and durable, allowing you to easily weave paper and store for a long time 3WEAR RESISTANT COATING: Spiral binding coils external adopt nylon coating, possess good surface gloss, corrosion resistance, wear resistance, with long service life 4PERFECT SIZE: Each strap coil is 3/4in in diameter and 0.8mm thick. Each spine has a 3:1 pitch and 34 double rings and can rotate 360 degrees 5BINDING OBJECTS: Use these double loop wire bindings to bind important documents, files, or reports for upcoming presentations or projects 50 x Spiral Binding Coils