non-metallic swimming pool structures being non-metal swimming pools; swimming pool structures incorporating plastic modules being non-metal swimming pools; swimming pools, non-metal structures, being non-metal swimming pools; set of ready-to-assemble non-metallic swimming pool elements being non-metal swimming pools; formwork, not of metal, for concrete being concrete retaining walls; building panels not of metal; staircases not of metal; reinforcing materials not of metal for building; swim...