Tetra Second Nature

UNASSEMBLED REPLACEMENT CARBON FILTER: Keeps aquarium water crystal clear ? removes s and discoloration.CATCHES DEBRIS: Dense, dual-sided mesh filters debris and fish waste.FITS TETRA WHISPER WATER FILTERS: Color coded to make it simple to remember which replacement cartridge size to purchase.CONVENIENT: Easy to assemble and easy to replace.USAGE: Change monthly or sooner if needed.