3 filter set which includes: one 5-micron
carbon pre-filter (TO1)
(change every 6 months),
one 0 .5-micron carbon block filter (CB1)
(change every 6 months),
one 15-micron granular
activated carbon post filter (R200)
(change every 6 months), or two 5 micron polyspun filters (RS4)
(change every 3
months),