ALEKO WHEEL4INCHVG V Groove Wheel for Sliding Rolling Slide Chain Gear Rack Gate Track 4 Inch Diameter Gold If you use V track assembly for your sliding gates, a good V groove wheel is essential to keep it working without a hitch Can be used with V track assembly of any material: stainless steel, galvanized steel, or aluminum High quality zinc plated steel wont rust or come loose, and never needs greasing or maintenance Designed for loads of up to 800 pounds Product dimensions: 4 inch diameter, 4 inch height; Color: Gold