ProFlex BioMedia Accessory Pack includes filter media and tray a trickle-down grid and bioballs. Used in wetdry setup. WetDry - Using the BioMedia Accessory Pack turn the ProFlex into a traditional wetdry trickle filter. Great for use in freshwater and fish-only saltwater applications to provide advanced biological filtration for a heavy fish load. For use with ProFlex Model 1.