The ring metal loose leaf binder is waterproof and rust-proof. What's more, it can prevent damage so it has long lifespan for you to use. Good materials:Made from multi-layer -plated stainless steel, the ring metal loose leaf binder is durable and reliable, and can be applied for a long time without being broken. Size: total size is 4 x 2.5 cm/ 1.57 x 0.98 inch, inner diameter is 2 cm/ 0.787 inch colour: gold Material: metal Package Contents: 12 x Book Rings Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.