Criticism made by my girlfriend: I tried this by chance and I do not regret my choice! a plug in the machine or by hand and hop more viruses and fungi microbes! it works perfectly at 30 ° 40 ° 60 ° 90 °! useful for disinfecting the machine in case of flu and other, in case of mycosis to wash your socks for example! remember not to leave it within reach of children! pity that the bottle is not bigger!