IN LINE RESIN FILTER REMOVES LAST TRACES OF DISSOLVED SOLIDS. Place in line after reverse osmosis membrane to reduce post RO TDS reading. If not used after a reverse osmosis membrane the expected life of the DI filter is significantly reduced. Highest grade mixed deionising resin which you can use as a final stage after reverse osmosis to further reduce the TDS. If you prefer the in line DI in the clear tinted housing per the 3rd listing image we have them listed as 130864313673. 2x Straight quick fit connectors are included with this item to allow you to connect it to standard 1/4" tubing [6mm outside diameter]. If you prefer 2x elbow quick fit connectors or 1x elbow and 1x straight connector send a message to us when checking out of and we'll dispatch accordingly. NOTE: This in line filter housing is not approved for use under constant mains water pressure and is meant for use with systems that are under intermittent pressure i.e. those connected to a garden tap or the end of a sink mixer taps and used periodically when required. This item is supplied with 2x ¼” npt threaded to ¼”tube [outside diameter is +/- 6mm] quick-fit connectors. You’ll need to apply 6-10 laps of plumbing tape on the threaded side of the fittings before use. Most people have a roll of plumbers tape on hand but if you don’t we sell a 15-meter roll on as item number 131310583559 and if you buy this item as well as the plumbing tape at the same time we will send them together.