Pentair R171016 Rainbow 300 Automatic Chlorine/Bromine Off-Line Pool and Spa Feeder Rainbow 300 automatic chlorine/bromine off-line pool and spa feeder Holds 11 large or 98 small tablets; treats 12,000 to 48,000 gallons Operates on pressure side of pumps Uses 1/4-inch feeder hoses, control valve and fittings Measures 14-3/4-inch length by 23-inch height by 22-1/4-inch width