... corrosion-proof and Gel Coat smooth finished,Ideal for water filtration MINDER GH Series Laminated Polyester reinforced with fiberglass sand ... for performance ,value and dependability ,which Ideal for water filtration of spa ,private or semi-commercial swimming pools, aquarium ... in operating , Non-corrosion S.S.316 screws assembling Maximum working pressure at 300KPA, burst pressure is up to 600KPA ...