Reservoirs are meant to be used with the Salt-Away Mixing Unit. They fit Part Numbers SAM, SAM12, SAMI & SAMI12. Smaller reservoir has capacity of 06 fluid ounces (177 mL). At Salt-Away's dilution ratio of 1:500 or 0.2%, area coverage is 1,450 sq feet (134.71 sq meters If used with a pressure washer, area coverage is 8,200 sq feet (761.80 sq meter). Larger reservoir has capacity of 12 fluid ounces (355 mL). At Salt-Away's dilution ratio of 1:500 or 0.2%, area coverage is 3,100 sq feet (288.00 sq meter). If used with a pressure washer, area coverage is 18,200 sq feet (1,690.83 sq meter).