Water Filtration Installation Pre-Packs work with both hot and cold water lines for standard and high-capacity housings. Standard Housing Installation Kits work with a standard housing equipped with a 3⁄4-in. NPT inlet/outlet. High-Capacity Housing Installation Kits work with a high-capacity housing equipped with a 1-in. NPT inlet/outlet. The Add-A-Line Filtration/Icemaker Installation Kit allows the installer to tap into a 1/2-in. CTS line and reduce to 1/4- or 3/4-in. O.D. tube sizes. The kits work with copper, CVPC and PEX.