Upgrade your existing central sponge blockor Answer fitted unit to the new Nexus Eazy. The Eazy features Evolution Aqua's solids removal system utilising static Kaldnes. The Kaldnes is retained in a 316 stainless steel enclosure and has been proven to trap incredibly small waste particles, without disrupting flow through the system. Cleaning the Kaldnes is a simple matter of turning on the air tap to the settlement area, thus agitating the static Kaldnes. Waste is then dislodged from the media, and purged through the central vortex drain. The Nexus Eazy 200 and 300 retro kit includes all the necessary parts, plus additional Kaldnes media to upgrade your exisiting Nexus filter. Note - This Retro Kit will only fit Nexus models manufactured prior to June 2006.