The Lifegard Hang-On Filter HOF offers a combination cartridge 2-Pack with Mechanical, Carbon and Biological Filtration Media. Easy to service and Easy to replace. It is designed to keep your aquarium water sparkling clean with three full stages of filtration while giving you the ability for surface skimming to remove floating debris. The Filter Cartridge is Three-stages:

Stage 1 – Is a 40 micron removable sponge
Stage 2 – Is Activated Carbon
Stage 3 – Is 20 Micron Filter Pad

This hang-on filter is designed to trap large debris at the sponge level that can be removed with periodic cleaning. The activated Carbon removes dangerous toxins and cultivates beneficial bacteria for a healthy environment and finally for fine debris there is a fine Filter pad.
Ideal for Freshwater or Saltwater Aquariums
Provides maximum surface for longer filter cycle
First stage mechanical sponge filtration effectively traps large debris like uneaten food and other organic materials.
Activated carbon for chemical filtration to effectively remove dangerous toxins while encouraging the growth of beneficial bacteria reducing harmful ammonia and phosphate build up.

Replacement Combination Cartridge 2-Pack for HOF Series Slim Design Hang on Filter