A single lever kitchen faucet with the handle in front, on top, or to the side of the spout adjusts water flow and regulates temperature. The lever activates one of three types of operating systems: ceramic disk, cartridges, or ball. Models might be installed as a stand-alone spout (sometimes equipped with a pull-down or pullout sprayer) or on a mounting plate. Lever placement might impact how well a single-handle faucet works, notes Consumer Reports (consumerreports.org). Their researchers found that single-handle faucets required the least effort to use, but those equipped with side handles were problematic. Users tended to hit their fingers on the backsplash when manipulating side handles. If their hands were dirty, that mess transferred to the backsplash or wall. With that said, most one-lever faucets comply with ADA (Americans with Disabilities Act) regulations because they are simpler to activate than two-handled versions. You’ll find most of these faucets in the $60-$600 range and in chrome or stainless-steel finishes, though they’re also available in bronze, nickel, brass, black, and white. Basic models tend to be low-profile, but gooseneck styles with side or pull-down sprayers can be found for under $100. Mid- to high-range faucets supply make-a-statement profiles, including statuesque spiral designs and multijointed wall units, and top-notch conveniences such as spouts that swivel 360 degrees, touch- and motion-sensor controls, water-saving and temperature-preset systems, leak-proof designs, and lime- and fingerprint-resistant finishes. Regarding shape, spouts range from classically understated to architecturally appealing. Traditional goosenecks and low-arch styles are done up in Victorian style or Tuscan-inspired patinas. Squared-off spouts top tall pillar bases; streamlined versions with moveable joints offer fold-up convenience. Levers also vary in shape (from flat to winged and cylindrical) and in size, so it’s important to give each faucet you’re considering a test run before you buy.