Replacement coarse blue sponge / foam suitable for OASE filtoclear, models 3000, 6000, 11000 and 15000 models.
OASE filtoclear 3000 requires 2 x coarse blue sponges and 1 x fine red sponges
OASE filtoclear 6000 requires 3 x coarse blue sponges and 2 x fine red sponges
OASE filtoclear 11000 requires 4 x coarse blue sponges and 3 x fine red sponges
OASE filtoclear 15000 requires 5 x coarse blue sponges and 4 x fine red sponges.
These are just the coarse blue sponges for the above models, please add how many you need of these and then purchase the number of red sponges you require