Features: Advantage: Made of high quality metal can withstand heavy use color unfading beautiful and anti-rust rings open and close easily and lock for extra security.Flexible design: Each one is well-designed namely it can be split into 2 halves and connect with a metal swivel nail tightly; So the book binders lock safely and tightly enough.Use for clip ring gate key installing shower curtain or loose leaf.Use: These metal binder rings suitable for classroom company office or home to fastening document stack notebooks paper cards home organization binding recipe sample book loose-leaf booklets contract or file etc.Easy to Operate: Pull to open and squeeze to close snap hinged binder rings with a locking mechanism that opens easily to add or remove materials.ideal for fastening any size document stack and keys and swatches.Vintage design: Bamboo joints shaped loose leaf binder is very creative elegant and retro suitable for DIY Album keychain scrapbooking crafts and gift journals memo filing binding.Package Includes: 2 Package Optional: Package A: Includes 7 Pieces Loose Leaf Binder Rings (20mm Inner Diameter) Package B: Includes 10 Pieces Loose Leaf Binder Rings (30mm Inner Diameter) Specifications: Material: Metal 20mm Inner Diameter: Approx.20mm/0.79 inches 30mm Inner Diameter: Approx.30mm/1.18 inches Type: 20mm Golden 30mm Golden 20mm Retro Dark Green Brass 30mm Retro Dark Green Brass note: 1.Please allow 1-2cm errors due to manual measurement make sure that you do not mind before you order.2.Due to the difference between different monitors the picture may not reflect the actual color of the item.