Material: This set of loose-leaf binder rings is made of metal with nickel plating on the surface. Strong nickel plating will not break, bend, or rust. Beautiful surface treatment with silver color makes it sleek and fashionable. Book Ring Size: These metal book rings are common sizes for use. 15mm/20mm/25mm book rings are available. 120 pieces, enough for office and daily use. Wide Applications: Widely suitable for home, office, or business to keep your messy documents or other small items in order and keep a tidy place. Keychains, scrapbooks, sample holders, and so on. Easy to Use: The binder ring consists of 2 parts and is connected by a rotary rivet, which is very easy to use. It only needs to be pulled to open and pushed to close. So it is a helpful and practical tool to keep your loose sheets organized. Tip: If you have any problems, please do not hesitate to contact us and we will get back to you.