This kind of ring binder has perfect disign,consummate technology,elegant appearence,low price and excellent quality. ring binder:O ring binder,D ring binderThe material of front cover :marble pvc,art paper,printing paper;Thickness of gray board:2.0mm,2.25mm,2.5mm and so on;The material of lining: pvc,art paper,printing paper;Our ring binder has perfect disign,consummate technology,elegant ...