Our Clear 10-Inch Add-On Canister Upgrade Kit is great for anyone that wants to add more filtration to their RO or RODI system. A standard RO/DI system will have three vertical canisters and a RO membrane on top. By installing our canister you can add an additional pre-filter sediment cartridge, carbon block cartridge, DI cartridge or Chloramine and/or VOC removal cartridge. Adding these additional cartridges will really help your filtered water quality. 1/4-inch quick-connect fittings and 5' of 1/4-inch tubing included. Item 540507.