Package Included: 100 pieces roman blind curtain ring; transparent plastic rings; Enough for you to use and replace, or you can prepare them as backup in daily life. Material: The transparent O rings are made of sturdy plastic, durable for long time using, easy to apply on shades curtains. Size: External diameter 13mm/ 0.51inch; Internal diameter 8mm/ 0.31inch, Thickness about 2.5mm/ 0.1inch. Color: The transparent color is invisible when you use it for blinds, which makes your blinds look clean and bright, giving you nice vision experience. Application: These plastic o rings can be applied for sewing onto reverse of roman blinds as cord guides; It also suitable for ceiling fans and light crochet craft decorations, the cord rings can help you to deal with multiple messy problems.