They are single-stage pump with complete drainage device, got 3C,CE,ISO,GS,ROHS certificates ... and steatite.Motor housing in aluminium L-2521.Windings impregnated with epoxy resin. Motor:Asynchronous, two poles.IP 55 protection.Class ... F insulation.Continuous operation.Built-in thermal protection BTP-A/B quiet-running centrifugal bathtub pump ;3C,CE,ISO,GS,ROHS certificates