23″ x 3-7/8″ filter brush comes with a support ring on the end for easy retrieval as well as to hang the brush in your filter chamber. Only a few of brushes or several together in a filter chamber can be used to filter out solids, depending on how the hobbyist wants to set up their system.
A good biofilter needs a lot of surface area with open spaces between for good aerated water flow. A high surface area is useless if the passageways are so small that water flow cannot penetrate.
The individual bristles are spiral wound to give a higher surface area and provides ultimate strength. These filter brushes do not sag or droop over time like inferior brands.