The roller balls of the shower curtain hook are made of acrylic (PMMA) and are strong, durable, available in a variety of colors and shining with a Yellow agate-like luster. The stainless steel shower curtain hooks rings are made of high-quality stainless steel, non-magnetic and rustproof, can be used in both indoor and outdoor environments. Shower curtain hooks surface is smooth and delicate, five balls rolling on the shower curtain rod, smooth and lightweight and silent. Simple and convenient installation. Shower curtain rod with a diameter of 25-32mm/1-1.3" can be selected. Name: Acrylic Roller Balls Stainless Steel shower curtain hooks rings Material: Stainless steel/ Acrylic (roller balls) Packing: Set of 12 pcs