This item is manufactured with premium plastic for and use. It is great for variety of uses such as loose-leaf, memo filing and sample holders. Multifunctional, multi colors and simple appearance, small in size, which is more convenient to use. Features -Color:Assorted Color -Material:Plastic -Size: 3.00X3.00X0.30cm/1.18X1.18X0.12in - Made of plastic, the loose leaf rings are and won't crack or split. - The book rings are great for variety of uses such as loose-leaf, memo filing and sample holders. - Easy to use, pull to open, squeeze to close, lock for additional security. - These plastic rings are perfect for documents organization and sorting. Different color presents the level of importance. Also suit for children learning cards sorting. - First find the seam on the book circle, then use your fingers to separate it in the opposite direction, then squeeze to close it. Package list: 80 x binder rings