50 PC Bulk 98209803 High Flow Manual Air Relief Valve for Pool FNS DE Filter. The Clean & Clear Plus (CCP100, CCP320, CCP420, CCP520), Quad DE (60/80/100), Pentair FNS, FNS Plus, SMBW 2000 & 4000 Series, and Predator filters are all particularly designed for these filters.
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