Yestore Roller Ball Shower/ door / Window Curtain Rings Hooks Set of 12 Easily slides along rod with one pull. 5 roller balls give space between the rod and hooks, providing an almost frictionless movement. Can be used as window / door / shower curtain rings hooks hooks are nickel-plated and corrossion-free and will last for years without rusting Color : White Acrylic; Balls Number : 5; Size : 8 mm Diameter Package with 12 Pcs/Set