Specifications: Quantity: 50 pieces hinged binding rings. Material: Iron metal. Color: Nickel plated, Silver. Inner Diameter: 25mm(1.0inch). Outer Diameter: 30mm(1.2inch).Easy to use: The metal book binder rings has 2 parts and is linked together by a swivel rivet, very easy to operate- just need to pull it to open and squeeze it to close.Wide applications: These loose leaf binder rings are very useful in our daily life: you can use them for loose-leaf, memo filing, key rings, scrapbooks, sample holders, etc.Notes: 1.The loose Lelaf binders are small parts, not for children under 3 years old. 2.Use them under adult supervision, do not leave your children using the leaf binder rings alone.