Our wire linewinders can be used with any size wire or cord (when making guying kits for example). These linewinders are made from a black nylon material reinforced with fiberglass fill. They are exceptionally strong yet lightweight. The series of 3 holes in a row are used for tightening guy lines -- just one pull and it cinches right up! The wings have slots to capture the wire when you want to quickly add or remove turns to adjust the frequency.