Replacement filter disk for the Bath Ball is made of non-toxic and recyclable kdf material. For optimal filtering, change once a year.
FITS EVERY BATH BALL WE EVER SOLD.
The most important thing to filter at the shower and bath is the disinfectant. Adding carbon means the filter will work on additional things, mainly organics.
The chlorine version BR-104 uses kdf 55. The chloramine version BR-104-85 uses kdf 85.
This is for the Bath Ball, not the Water Ball.