Pentair R171066 Rainbow 300-29 Automatic Chlorine/Bromine Off-Line Spa Feeder Rainbow 300-29 automatic chlorine/bromine off-line spa feeder Includes triple-capacity 29-inch chamber and treats 14000 to 57000 gallons Operates on pressure side of pumps Uses 1/4-inch feeder hoses, control valve and fittings Measures 7-inch length by 40-1/4-inch height by 7-inch width