Square solid basic | EHEIM GmbH & Co. KG. Leading aquarium manufacturer.
EHEIM professionel 4+ 250T | FRESSNAPF
Compatible Coarse Prefilter Pad Fit for Eheim Professional 3 250/250T/350/350T/600 2071/2073/2075 and Eheim Pro 3e 350 2074 - AliExpress
Amazon.com : LTWHOME Replacement Coarse Blue Pre-Filter Foam Fit for Eheim Pro 3 250, 250T, 350, 350T, 600/ Ultra G Pro 3 Filter 2071,2073,2075 and Eheim Pro 3e 350/2074 (Pack of 6) : Pet Supplies