This Whole of House system is an excellent performer and yet very cost effective. Used in both Rural and City Properties. Suitable for all our 20" X 2 1/2" Dual Gradient or Carbon Block cartridges. Suitable for smaller homes with up to 40 LPM flow requirements. Package includes 2 x 20" STD H/Duty Housings, Twin SS Bracket with SS screws, spanner and a 3/4" nipple housing joiner. When installing into a town water supply a pressure limiting valve must be installed before the filter housings. Please note there are no filter cartridges included in this package.