20 ring metal binder, metal 20 ring clip, 20 ring binder clip metal ring mechanism/metal multi-ring mechanism/metal ring binder item: TR210-20-25/17 material: metal color: nickel length: 218mm height: 30mm width: 17mm inner diameter: 20mm outside diameter: 29mm binding thickness: 20mm packing: 300pcs/ctn metal ring mechanism/metal multi-ring mechanism/metal ring binder