Evolution Aqua is a reputable manufacturer of high-end filtration systems that guarantee dramatic improvement in a pond’s water clarity level. An example of a great product from the brand is the Nexus Filtration System. For this product, a spare part called the Air Ring Complete Nexus 300 has been made to suit the needs of the Eazy Main Body. It works with other parts to create cleaner and healthier koi ponds. At Everything Koi, you can purchase Air Ring Complete Nexus 300 at the most competitive rates.