Standard faucet style that has been in the industry for more than 10 years. The black lever can be pressed for on demand water flow or flipped up to have a steady stream of water. Air-Gap faucets available only for Chrome and Brushed Nickel faucets. What is the difference between Air-Gap and Non-Air-Gap faucets? Air-gap faucets have 3 tube connections coming from the faucet while onlyNon-air-gap faucets have only 1 tube connection. Air-gap faucets are capable of preventing back-flow in the system. Specifications: Minimum size hole in counter-top: 5/8" 1/4" tube connections Click here to enlarge