Features 100% Brand new! Premium quality. These loose-leaf binder rings for books are made from nickel-plated metal, not easy to deform or break, and can withstand long term use. Multiple sizes available. 20mm, 25mm, 30mm, 38mm, 45mm, 50mm, 55mm, 70mm, 88mm book rings. Assorted sizes metal rings can meet your different using needs. Easy to open or close. The steel metal round ring is held together by a central swivel rivet, convenient to pull to open and squeeze to close, you can use them easily and quickly. Closed tight and let your books organized. Widely used. The books binder rings are ideal for loose-leaf, memo, paper cards, scrapbooking, binding recipe, DIY projects or other loose-leaf items. Specifications Material: Nickel-plated metal Color: Silver Size: Approx. Diameter: outer 20mm/0.79", inner 16mm/0.63", Thickness: 2mm/0.08" Diameter: outer 25mm/0.98", inner 20mm/0.79", Thickness: 2.2mm/0.09" Diameter: outer 30mm/1.18", inner 25mm/0.98", Thickness: 2.2mm/0.09" Diameter: outer 38mm/1.50", inner 32mm/1.26", Thickness: 2.7mm/0.11" Diameter: outer 45mm/1.77", inner 38mm/1.50", Thickness: 3mm/0.12" Diameter: outer 50mm/1.97", inner 45mm/1.77", Thickness: 3mm/0.12" Diameter: outer 55mm/2.17", inner 50mm/1.97", Thickness: 3mm/0.12" Diameter: outer 70mm/2.76", inner 62mm/2.44", Thickness: 3.2mm/0.13" Diameter: outer 88mm/3.46", inner 80mm/3.15", Thickness: 4mm/0.16" Attention Please allow tiny size deviations due to human measurement. Due to the effect of light and monitor's brightness, there may be slight differences between the color tone of the photo and the actual item! Please keep the binder rings far away from water and the acidic substance. Please keep the metal rings out of reach of children and pets to prevent swallowing and pinching. Package Included 15/30 x Loose-Leaf Binder Rings