Rustproof & Long-lasting: These metal binder rings feature a multi-layer nickel-plated finish for enhanced durability and rust resistance. Smooth laser-polished edges prevent scratching during use. Each ring is designed to withstand over 10,000 openings and closings. Standard Size: Package includes 80 loose leaf binder rings. Outer diameter: 25mm (1 inch), inner diameter: 20mm (0.8 inch). Each ring holds up to 140 sheets of paper. Easy to Open/Close: Designed for ease of use. Hold both ends and push one forward, the other backward with slight pressure to open or close. Securely holds flashcards, papers, and more without loosening. Extensive Use: Ideal for organizing loose-leaf papers, flashcards, books, memos, filing, keychains, and other small items. Keeps materials neatly arranged. Lock-Tight Design: The movable opening features a secure locking mechanism that stays firmly in place during use, preventing dislocation and keeping contents secure even with frequent handling.