This Anello clip rings will slid smoothly on any metal rod with diameter up to 1"(24mm). Equipped with high tension clip, you will be able to hang extra heavy curtain without worry.<br> <br> We recommend spacing rings approximately every 4 inches. To determine the number of rings needed, divide the rod width (in inches) by 4, round up, and add 1 additional ring for each panels leading edge. If hanging pinned pleated panels, plan for one ring for each pin hooks. Product Dimensions 3.0 x 32 x 38 mm