They are single-stage pump with complete drainage device, got 3C,CE,ISO,GS, ... motor mountings in polypropilen.Motor shaft in stainless steel AISI-420.Impeller in polypropilen.Mechanical seal in graphite and steatite.Motor housing in aluminium L ... protection.Class F insulation.Continuous operation.Built-in thermal protection BTP-A/B quiet-running centrifugal bathtub pump ;3C,CE,ISO,GS,ROHS certificates