Waterway 2.0 HP Executive Spa Pump Wet End [2" MBT X 2" MBT] [56 Frame] (310 1720) airsupply It is used when servicing It is used when servicing worn The PresAir Trol side spout pressure switch is designed for compatible systems that use a 1 8 inch barb connection and need an SPDT pressure activated switch rated at 21 amps A wet end like this is useful because it restores the complete hydraulic side of the pump while preserving the larger 56 frame fit of the original assembly this Waterway wet end is a practical replacement when the complete 56 frame wet side assembly with 2 inch MBT by 2 inch MBT connections needs restoration