Leviton 48211-WVC Digital Volume Control Wall Unit, White No direct speaker/amplifier connections required at the volume control wall unit Digital, transformer-free design uses aerospace-grade Cermetile resistors for proper heat dissipation and superior performance Selectable boot-up feature allows automated volume level control upon powering of the stereo system Microprocessor controlled relays for silent switching Tap mute feature activated when pressing center of rocker switch