Filter 301 (12 pack) #AD301-3210 (large/version 1)

The round air filter mounted on the bottom of all Rena Air model pumps should be replaced when dirty to avoid damage to the air pump valves and increased clogging of diffusers. The 301 series pumps use either large version (pictured above) filters or the standard size filters ( 702C1 ) found on the Rena Air series pumps.