Not all units come with a faucet adapter. Most come with a hose thread adapter which will screw on a outside hose bib, garden hose, the washing machine cold wate rsupply faucet or many laundry sink type faucets. Most kitchen or bathroom faucets require an adapter that can be bought either from the RO vendor or most any hardware store for between $5 and $15 depending on the adapter style. I prefer hooking them to the washing machine cold water supply using a brass Wye adapter like you use to hook two garden hoses to a single hose bib or faucet. Many of the wye adapters have individual valves so you can shut the RO/DI off without having to disconnect it and you can send the waste to the washer drain, a laundry sink or even some of it can be used to fill the washer if you monitor the flow. The wye costs $3 to $5 at Lowes or HD. The $120 Spectrapure RODI-90-REFURB comes with an inline pressure gauge and hose thread adapter standard and it is a good idea to add a handheld TDS meter for $25, it does not come with an inline TDS meter or handheld. It will produce about 3 to 3.5 gallons per hour at 50-60 psi so the faucet adapter will tie up a kitchen or bathroom faucet for a good amount of time if you need to make much water.