The Streamline moisture trap keeps unwanted moisture and condensation under control , and protects against damp musty odours and mildew. It is designed to fit onto window sills and narrow surfaces. It is a sturdy container that is neat and clean .To use simply empty the crystals into the top section and close the lid.It is ideal for caravans, boats, utility rooms, kitchens , bathrooms , wardrobes, cupboards to mention a few.