120 Sheets Capacity: This double coil binding spine can hold up to 20 sheets of 70g A4 paper, which is very practical and can be used for a variety of situations. 2Iron Inner Wire: This double coil binding spine is made of iron wire, which is sturdy, wear resistant and not easy to damage, and can be use for a long time. 3Nylon Coating: This double coil binding spine is nylon coated for a glossy surface, erosion and abrasion resistance, and a long service life. 46. 4mm Diameter: This double coil binding spine has a diameter of 6.4mm and a thickness of 0.8mm, each spine has a 3:1 pitch and 34 double rings that rotate 360 degrees. 5Wide Application: This double coil binding spine has a wide range of applications, and can be used for documents, books, notes, reports and more. 100 xDouble Loop Wire Binding Spine