Enhance your system's performance by controlling your in-boat and tower speaker volumes independently with Roswell's Dual Zone Volume Control. The Dual Zone Volume Control allows you to have a conversation in the cockpit while your rider rocks out behind the boat, or pump up the music in the cockpit without waking up the neighbors with your tower speakers. Independent volume control. Notches on control knobs give a tactile feedback. Easy to install with surface-mount or flush-mount options. Easy to install Surface-mount or flush-mount options