EZ BIO Core Pump Pre-Filter Size: 20 Double - Up to 3400 GPH Pond pre-filter using Matala media 7.9 x 7.9 inches Maximum flow allowed 3405 GPH Provide mechanical and biological filtration 1-1/2" FPT inlet or includes adapter for 1", 1-1/4", or 1-1/2" Tubing