Rival 4 stage upgrade kitThis dual clear housing comes complete with the sediment and carbon filter (not pictured). To upgrade your 3 stage cart to a 4 stage simply remove the bracket and carbon pre filter from your 3 stage and install this bracket and filters in their place. The hardware that is currently holding your carbon pre filter bracket in place will hold this new bracket in place so no need for any additional hardware. 10" Carbon Filter Benefits: Higher Filtration