This low cost simple device is fitted as standard to all Sunliners, but Winnebago owners sadly seem to miss out on this one. What this gadget does is to store water under pressure, and then release it on demand. This almost stops what is called "short cycling" of your pump - a sort of water hammer. The gadget is made by Shurflo, and pricing starts around the $70.00 mark. You definitely don't need a huge one to suit the average motorhome. Mechanically it consists of an elongated sphere separated by a bladder in the centre. One end has an air valve as found on all tyres. You put air pressure into this. When your pump runs it has the effect of pumping up the bladder and compressing the air. This actually stores energy and allows the pump to flow at a more consistent rate. You really notice the difference when using low flow rates such as showers taken using just a dribble of water to conserve it. Just place it as close to the pump as possible and in the DISCHARGE line. Can be mounted at any angle or even upside down. You do need access to the Schraeder valve in case you need to increase the air pressure. Readily available from, Camec, Caravan Accessories, Award, Coast to Coast etc. Dearest in marine outlets for some odd reason - $114.00! Ouch!!