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 [Max]: 1"; Sheet Capacity: 175; Color(s): Black.