... line is spa cover ,outdoor spa cover, hot tub cover ,bathtub cover, swim spa cover, swimming pool cover ,lifter for cover ,PVC water pipe and related ... % high density insulation foam.3) Competitive price: we are one of the largest professional manufacturers of spa cover in China ... and corrosion proof, ensuring structural integrity for the life of cover.5) Corrosion Proof Nylon Zipper: Large #8 zipper ...