Quantity: totally 20 pack silver metal curtain rings in the package, enough for daily life and replacement Curtain ring: outside diameter is approx. 40 mm, dimension inside diameter is 32 mm , please make sure the size when you buy it Installation: curtain ring go through the curtain rod one by one, and curtain hooks into the small ring, then you can try to sliding the curtain easily Good design: curtain ring are nice polished and surface without burrs, and silver heavy duty metal curtain rings for your curtains, please be assured the application Wide application: the curtain rings are widely applied for most kinds of curtains, such as shower curtain, window curtain, french window curtain and so on Please make sure the size before you buy it