Stainless Steel Door Window Silent Nylon Pulley Slot Wheel: This Product Features A Stainless Steel Construction With A Silent Nylon Pulley Slot Wheel, Ideal For Sliding Door Fittings And Glass Door Sliding Rollers.Nylon Sliding Door And Window Roller Wheel: Made From Iron And Nylon, This Roller Wheel Is Designed For Smooth Operation And Durability.