35 The bringing together, for the benefit of others, of sand, gravel, crushed stone, asphalt, bitumen, cement, gypsum, plaster, concrete, marble blocks for construction, building materials (as finished products) made of concrete, gypsum, clay, potters' clay, stone, marble, wood, plastics and synthetic materials for building, construction, road construction purposes, non-metallic buildings, non-metallic building materials, poles not of metal for power lines, barriers not of metal, natural and synthetic coatings in the form of panels and sheets, being building materials, bitumen cardboard coatings for roofing, bitumen coating for roofing, doors and windows of wood and synthetic materials, traffic signs not of metal, non-luminous and non-mechanical, for roads, monuments and statuettes of stone, concrete and marble, building glass, prefabricated swimming pools not of metal (structures), aquarium sand, enabling customers to conveniently view and purchase those goods, such services may be provided by retail stores, wholesale outlets, by means of electronic media or through mail order catalogues