Features & Benefits: High Quality: Made of durable, long-lasting materials, can withstand heavy use. Strong nickel plating won't crack, bend or rust Wide Compatibility: Loose leaf binder ring is a wide application office supply, great for variety of uses such as loose-leaf, sheets, memo filing, memos, invoices, key rings and sample holders Easy to use: Rustproof book rings are user friendly: pull to open, squeeze to close, lock safely Size: loose leaf ring inner diameter: 3.5"; Outside Diameter : 3.9", Applies to loose-leaf book, memo filing, key rings, scrapbook, sample holder or other loose-leaf items Packing Includes: 8pcs loose leaf binder rings