The visible parts of the pump acting solid stainless steel, but inside, water-filled part of the pump, it is so at the end. The thread of the attachments and their internal fittings are made of cheap, stainless steel. And keep away over time rust in the water.
I now had the fax thick and have bought a (hopefully) sensible pump from another manufacturer, after my complaint mail with detailed description of the damage and meaningful pictures of the manufacturers quite ignored and a subsequent written appeal to the Board with a 08-15 mail was answered.