Material: Galvanized iron, color silver Ball material: Nylon Ball diameter options: 16 mm (0.5 inch), 25 mm (1 inch) Dimensions: 48 x 32 x 20 mm (L * W * H) for 16 mm ball; 75 x 50 x 30 mm (L * W * H) for 25 mm ball Package includes: 4 x roller transfer units, 8 x screws, 1 x screwdriver High-quality materials: The main body of the ball transfer unit is constructed from galvanized carbon steel, offering scratch resistance, corrosion resistance, and rust resistance. Durable and long-lasting. Smooth operation: Features a nylon ball that rotates 360 degrees freely, enabling effortless movement of goods. Provides smooth, low-friction rolling performance. Quiet performance: Roller ball bearings are polished during manufacturing to ensure a smooth surface, minimizing noise during operation. Rolls quietly and efficiently. Heavy-duty load capacity: Each caster supports up to 15 kg, making it suitable for a wide range of lightweight to medium-weight applications. Easy installation: Designed with two mounting holes for secure screw attachment. Compact design fits into tight installation spaces. Wide application: Ideal for use in furniture such as sofas, cabinets, shelves, display cases, carts, and kitchen appliances. Also used in industrial settings including conveyor systems, packaging machines, processing equipment, and auxiliary machinery.