Curtain Rod Rings -- Outer diameter is 46 mm, inner diameter is 38 mm/ 1.5 inch, fits rods up to 35 mm (1-3/8\") in diameter. Suitable for all types of rods. Smooth Gliding & Glossy Finish -- Curtain rod rings feature finely polished smooth surfaces with no burrs, ensuring effortless gliding of your curtains. Eyelet Design -- Curtain rings have a round eyelet that keeps curtain hooks or clips in place and prevents them from falling off while keeping your drapery in good condition. Wide Application -- Curtain gliders and rod rings make it easy to hang most types of curtains, such as shower curtains, window curtains, French window curtains, and more. Easy Installation -- Attach curtain hooks to the curtain rings and slide the rings onto the curtain rod one by one. Metal drapery curtain rings work well with all extendable and non-extendable rods.