Every feature of the Whisper EX has been designed with simplicity and convenience in mind. This is truly the intuitive filtration system. Simple Set Up - Ready to go right out of the box. No priming required. Scientifically Engineered Water Flow. Continuous flushing action prevents debris buildup.Outflow maximizes water agitation and oxygenation. Whisper EX Filtration Systems use Tetra EX Carbon Filters.