Powerwinch Saltwater Series Jack - 1500lb, Bolt-On, Single Wheel, Zinc 500+ HR Salt Spray [21600-J-1500-B1-Z-R]Saltwater Series Jack 1500lb, Bolt On, Single Wheel, Zinc 500+ HR Salt Spray The Saltwater Series Trailer Jacks are designed for marine applications where exposure to saltwater and corrosive conditions is common. These jacks feature a 500 hour salt sprayrated zinc plated coating that provides enhanced corrosion resistance compared to standard finishes. Like the Select Series, Saltwater Series jacks include a pivot pin sleeve for dependable pivot