post binder of metal, plain surface post binder material: iron/metal color: nickel, electro-plated size: 2 post binder: width available: 40mm, 50mm, 60mm, 70mm, 90mm, 115mm 3 post binder: width available: 40mm, 50mm, 60mm, 70mm, 90mm, 115mm 4 post binder: width available: 40mm, 50mm, 60mm, 70mm, 90mm, 115mm OEM service available free samples offered.