This is a practical and sturdy nylon roller balls, which are made and material, not easy to damage and break, with creative design and sturdy structure. Come with enough quantities for your needs, with simple installation method, suitable for many kinds of furniture. Features -Color: Silver. -Material: Carbon steel, nylon. -Size: About 3.25X3.25X2.05cm/1.28X1.28X0.81inch. -Specification: CY-19A. -Come with enough roller balls for your daily needs, with simple installation method. -Stable and firm, with good hardness and high performance for long time use. -Made and material for sturdy and practical use, not easy to break and damage. -Designed with fine craftsmanship and delicate details, with high performance and good hardness. -Feature with high-speed and stable operation, with good load bearing capacity. Package list: 8 x roller balls