Tetra Whisper EX45 Power Filter and Replacement Carbon Filters Bundle Whisper EX45 Power Filter and 4 Pack of Replacement Carbon Filters 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.