I have this evaporator heads already ordered about 8 times. And had only a single loss. Otherwise, these are of perfect quality. Although one does not want me, I sink with hot water, and after a few minutes he goes again (until the water is completely expelled).
Realistically, I would say you have to replace the head every 7-8 days with this product here. If you so much as I concentrated. Occasionally he stops determined 14 days. But everything is relative. Here still seems (good old) Joeytech quality to exist.