Size & Load Capacity : 4" diameter, 1 13/16" thick, double-sealed bearings, supports up to 3500 lbs. Ideal for large driveway and security sliding doors with inverted V tracks. Maintenance-Free : Sturdy steel V-groove wheel with high-temp sealed bearings. No greasing or maintenance needed. Easy Installation : Welded bracket box allows direct attachment to gate frames. Replaces old wheels, extends gate system life for indoor/outdoor use. Corrosion-Resistant :? Galvanized wheel and powder-coated bracket box protect against rust and corrosion, ensuring smooth operation and reduced maintenance. Versatile Use : Suitable for all sliding gates, rolling doors, towing, gym equipment, and moving heavy loads on V-tracks.