17 Rubber, gutta percha, gum, asbestos, mica, and goods made from these materials and not included in other classes; plastics in extruded form for use in manufacture; packing, stopping and insulating materials; flexible pipes (not of metal); Rubber, gutta percha, gum, asbestos, mica, and goods made from these materials and not included in other classes; plastics in extruded form for use in manufacture; packing, stopping and insulating materials; flexible pipes (not of metal)