Fulton 1200 lb Bolt-Thru Swing-Away Trailer Jack with 6" wheel The jack is designed to be used with marine and utility trailers. The mount fits up to a 3" X 5" trailer frame. It is made of a heavy gauge steel and a proprietary bushing material for a mount with minimal deflection and maximum support. The 1:1 sidewind gear rotation provides fast and easy operation. This includes all necessary mounting hardware.