Heyrex Torus watering bowls store up to 2L of water inside their reservoir walls, filtering the water as it automatically dispenses. Its large capacity means less filling and its low profile means less spills or mess. Heyrex has lock, fill and drink functions making it ideal for travel. Heyrex does not require batteries or a power source and has a 12 month warranty. Each bowl comes with one carbon filter and the range includes replacement filters.