Under-Sink & Countertop Filtration by Waterdrop. Please note that this Undersink Water Filtration System cannot reduce TDS. If you need to reduce TDS, the Waterdrop RO System will be an excellent choice. TDS stands for total dissolved solids. It is composed of inorganic salts and a small amount of organic matter. This filter cannot lower the TDS value because it removes harmful substances while retaining minerals such as potassium, calcium, sodium, and magnesium, which are beneficial for your health. What’s in the box? ·Waterdrop Undersink Water Filtration System×1 ·Inlet hose×1 ·Outlet hose×1 ·3/8’’–1/2’’ Convertor set×1 ·Self.