These loose-leaf binder rings are mainly used for the production of handicrafts. It is made of metal materials and can be used safely. You can apply these accessories to make kinds of handicrafts with your friends or family members together, enjoy the interesting handmade process. Features -Color:Silver -Material:Iron -Size:3.00X3.00X0.20cm/1.18X1.18X0.08in -Inner Diameter:25mm -Outer Diameter:30mm -The rings open easily and lock for extra security. Pull to open and squeeze to close. -Closed tightly, easy to open and lock. Perfect for DIY your notepad, planner, calendar, etc. -Sufficient quantity for your daily use, or practical and delicate those people who love DIY making. -You can easily link a large number of loose-leaf brochures, paper cards, name tags, instruction guides, etc. -You can also use these binder rings to diy book, sample book, scrapbook, sample holders, contract or file. Package list: Binder Rings