Design: The curtain rings large ring for curtain rod, the small ring for curtain clip Installation: Curtain ring go through the curtain rod one by one, and curtain hooks into the small ring, then sliding the curtain easily Application: Widely applied for most kinds of curtains in various colors, heavy curtains or lightweight curtains Make full use of the heavy duty metal and strict design, bearing good, and never deformation or drop out suddenly. Nice ed and smooth surface without burrs to catch on your curtain, eliminate snagging, tugging and pulling of the curtain. Internal diameter: 38 mm, fit for 33 mm curtain rods Outside diameter: Approx. 45 mm Size of the rings: line width about 4 mm Small ring internal diameter: 6 mm Color: Black Material: Iron Package Contents: 40 * Curtain RingsOnly the above package content, other products are not included. Note: Light shooting 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.