Internal diameter: 1.5 inch/3.81cm. External diameter: 1.77inch/4.5cm Rings Thickness: 0.12 inch. Fits diameter 1.38inch curtains rod. Package Includes: Set of 40 Copper Metal Decorative Drapery Curtain Clip Rings 1.5 inch internal diameter For hanging curtain, party light, copper wire, christmas light hangers, flashlight, lanterns, tent and so on. Perfect for luxury hotels, restaurant, bar, meeting room, bedroom etc.