Microline - with Base - Faucet Long Reach Air Gap S1089-08 for easy installation from above the sink.3/8" Quick Connect to the Water line.Direct replacement for similar Microline Faucets. Current manufacturer part number is R7100-CR ( chrome finish ).Has connections for three lines used with "air gap" type Reverse Osmosis installations. Air Gap style faucets are required by most "plumbing codes", and are standard with Microlline Reverese Osmosis systems. Some other brands do not use this type of faucet. Also, many installers prefer using a Non-air Gap style of faucet. In such installations the drain line does not run up to the faucet, but is connected directly to the drain clamp under the sink.Faucet Installation Guide