A range of high quality attenuators supplied complete with plastic surface mount back box. The stylish ABS faceplate is fitted with a matching plastic knob. Each attenuator is fitted with a 24V relay to enable bypass to full volume when triggered from a fire alarm panel.Attenuation[tab]3dB per graduation[br]Frequency response[tab]35Hz - 20kHz[br]Relay[tab]24V, 50mA[br]Dimensions (assembled)[tab]85 x 85 x 75mm (inc. back box)[br]Mounting depth[tab]47mmPower[tab]24W[br]Weight[tab]230g