25W volume attenuator VT-325E is high quality wall plate controller for 70v/100v commercial acoustical system, it has 11-step control for the sound, with relay control, EMC signal can be triggered by DC input to ARTONE audio attenuator or volume controller. The rectangular wall panel shape is stylish for American, EU, Middle East, South-east Asia, Oceania region use for better sound adjustment in the room.