Good afternoon,I have given for my grandma a 2l abf foam extinguisher for the kitchen,and 1 need other 2 units(small of course),even a 2 litre size is heavy for her,I was thinking the one at the corridor a 1 litre water mist and the second one at the living room the thing that worries me if this unit extinguishes only too small fires ,it hasn't got an a rating only a "5f"thanks very much.