Minder" filberglass sand filters are constructed by the latest engineering technology. The improvement of flowability provides an ultra-pure water filtration. The fiberglass winding design allows the filter to have extra strength and resistance to chemical and corrosives. "minder" fiberglass sand filters are the most recommendable equipment for the application of swimming pool and spa. Features: 1. Fibreglass reinforced tank with uv resistant surface finish. 2. Internal surface of the tank is finished with water resistant resin. 3. Spherical tank with uniform wall thickness. 4. All sand filters with pressure gauge. 5. 1-year tank warranty.