Set of 3 moistening brushes for the Phoenix Electronic E1, E2 series.
This set of brushes is for all Phoenix electric models, Phoenix E1 and Phoenix E4. These should be replaced if they are worn down, or filled with glue and can't be washed out anymore. For instances of a lot of build up, you can try soaking the brushes overnight to break up the gunk.
Replacement recommended every 3-5 years.