Laminated sand filter for he filtration and purification of the water of medium and large swimming pools. Incorporated in the lid a pressure gauge and a cap with screws for a tight seal. In the lower part of the filter it includes a drainage cap for emptying the filter of water for maintenance and sand replacement. The Alaska filter has 4 different model sizes in this series (500mm, 600mm, 780mm and 900mm diameter). It is ideal for inground pools and swimming pools medium and large construction (Also for community pools and semi-public)