Unger Ultra Resin Filter Pack For Hydropower L. Over 30% more pure water per resin filling. For Hydro Power Ultra Filter L, LC. Every Ultra resin pack contains a pre-portioned amount of UNGER premium ion-exchange resin. New formula, perfected for glass cleaning. The FloWater technology 2.0 in every Ultra resin pack ensures and efficient flow of water through the whole tank which optimises the resin saturation. Code: UNDIUB3