The simple Check Valve / Airgap Adapter creates a bypass for your RO unit's drain line and makes the air gap faucet unnecessary.
The picture shows all you need to know about installation. The only tool you'll need is a pair of scissors.
The white tube represents the small drain tube that comes out of the membrane housing and goes up to the faucet. The black tube is the 3/8" tube that runs between the base of the air gap faucet and the drain saddle. Just clip at a convenient place. Make a good, square cut on the tubing. Then join the two tubes together with the adapter. No special elevation or placement is needed. After installation, your faucet will have only one tube (in most cases a 1/4" tube) that connects it to the "permeate" product water (the water you're going to drink) of the RO unit.
(whole house & well units)