possible hose filter dislodged in a tefal steam generator?

Hi,
During the water rinse to remove scaling from my steam generator iron, I heard rattling and when I shook it to empty the contents of the boiler tank a strange (about 3.5 cm) object fell out that looks like a mesh filter that might fit into a hose.
Can anybody explain what this is and if it is replaceable?
many thanks.