Waterway 4.0 HP Viper Spa Pump Wet End [2 1 2" MBT X 2 1 2" MBT] [56 Frame] (310 0140) nutsboltsscrews A retrofit control system can A retrofit control system can be a smart solution when an older spa needs a broader refresh instead of one more temporary fix and pressure switch relationship give this heater practical value because heater assemblies work best when their electrical A wet end like this is useful because it restores the full hydraulic side of the pump while keeping the larger connection format and 56 frame design used by the original Viper assembly Complete wet end replacements are especially practical when the wet side has broader wear and the motor remains serviceable