An in-line accessory faucet having a separable plastic air-gap module for use with a reverse osmosis unit, the faucet being installable without the module when used without a reverse osmosis unit. The air-gap module slides onto the faucet pipe conduit below the housing, and has brine flow passages and...http://www.google.com.au/patents/US4635673?utm_source=gb-gplus-sharePatent US4635673 - Accessory faucet
