C-Rings for 1 1/2 inch diameter indoor or outdoor curtain rod. Use to slide past support brackets. Available in two colors in stock, ready to ship. It can be used indoor or outdoor. Use on those windows that face patio or pool area, or use inside on any window. Charleston collection by Design Elements. Finish: Powder coatedMaterial: Metal Use indoor and outdoor2 inch inside diameter, 2 1/2 inch outside diameter. Priced each.