Although there are many external pumps to choose from, none provide the complete package the way Sequence does. Sequence pumps..."Genuine by design" Versatility, Safety, Quality, Economy, Quiet, Motors are totally enclosed for maximum protection, design provides for ultra low watt consumption, along with low temperature rise, Reliability and Efficiency. These are the work horses of the industry. They provide tremendous flow rates, with enough pressure (head) to handle the requirements of most systems with biological filters and moderate height waterfalls.