Ultralift's polyethylene tanks, designed and manufactured by Hydrohoist, are highly resistant to impact or low-water damage, flexing when stressed, then returning unharmed to their original shape! And, all of Ultralift's steel parts are above the water--a completely new concept in the boat lifting industry--to defy rust, corrosion, and the elements, and protecting your boat for years of convenient and carefree storage. The Ultralift--the ultimate in boat lift performance!