The US Tower HDX series crank-ups are extra heavy duty steel towers. They are suitable for even very large amateur antennas and arrays. These towers are constructed using 21 foot sections with a four foot overlap where sections meet to increase strength and prevent binding. They accommodate most large rotators, and still allow full retraction. All U.S. Towers are hot dip galvanized to resist rust and corrosion, providing years of use. All are supplied with a T-base, base bolts, installation template, rotor plate, and top plate. All non-motorized models include a load actuated hand winch. The HDX-572MDPL is supplied with the MDPL-1000 motor drive. The HDX-589MDPL is supplied with the MDPL-1000, and the MCL-100 limit switches.