Designed for use with the Remora Pro Protein Skimmer with Mag 3 pumpThe AquaC Remora Surface Prefilter is a special box designed to hide the skimmer pump, thereby creating a more aesthetically pleasing aquariumSkims water off the top of the tank, which is often coated with a heavy load of organics. This can improve skimming by as much as 20% (much darker, smellier foam), and the prefilter has a slotted edge just like an expensive overflow boxContains a bubble eliminating sponge to get rid of those micro-bubbles that sometimes escape back to the aquariumWater return area can also serve as a media chamber for those who choose to use activated carbon or phosphate removing compoundsSurface Prefilter installs in seconds and requires no tools