Nylon-Coated Double OO Wire -- Made of good quality steel with nylon coated; Full range of specifications: Diameter from 3/16 inches to 2 inches; Wide choice of colors-8 standard colors; 2: 1 & 3: 1 pitch available; Avaible in box (A4, letter & legal size) and in spool; Suitable for all kinds of document, notebook, diary book and calendar binding.