A shampoo bowl is a specialized type of sink typically found in hair salons and barber shops in nursing homes and long term care facilities. These sinks have curved cutouts designed to accommodate the back of a person's neck while his or her hair is washed. Shampoo bowls are typically plumbed into the water supply and sewer or septic system, just like other sinks.  Essentially, shampoo bowls are sinks, with a water supply, faucet, drain, and often some type of sprayer.
VMS stocks a chrome plated single lever shampoo faucet with a spray hose and vacuum breaker.