MATERIALS: The rolling gate wheel is made of high-quality PU and anti-corrosion steel, sturdy and durable, with anti-oil, anti-corrosion, and anti-rust properties. DIMENSION: Total mounting height is 25.5 cm; wheel diameter is 5 cm; mounting plate size is 7.54.5 cm (LW). LOAD CAPACITY: Each caster supports a maximum load of 50 kg. SPRING-DRIVEN DESIGN: The retractable gate wheel allows 6 cm of vertical movement, automatically adjusting to uneven surfaces to prevent sagging and ensuring the gate remains in contact with the ground for smooth operation. EASY TO INSTALL: Includes 4 bolts. Heavy-duty universal mounting plate with 4 holes fits wooden garden gates, driveway gates, and yard fences. Note: All measurements are manually taken; please allow 13 cm variation. Due to lighting and display differences, slight color variations may occur. Actual product may vary slightly from images.