Vinyl is reinforced with heavyweight board that stands up to the toughest use. Heavy-duty round ring mechanism holds contents tightly in place. No ordinary casebound ring binder, this heavyweight storage giant holds its shape?even when subjected to rough, constant use. Equipped with DublLock? locking round rings to secure sheets without gaps. Three rings with metal hinge construction for extra-strength durability. Capacity Range ("): 0 in - 1 in; Sheet Capacity: 175; Color(s): Black; Binder Sheet Size: 11 x 17.