The ATP-Series of attenuators allows the output level of a network of 25 V or 70 V speakers to be controlled from a wall-mounted volume control, without affecting overall amplifier volume settings. A bypass function overrides the volume control knob setting when activated by 9V to 30V DC. Applying 9 V to 30 V DC between pins labeled D+ and D- bypasses the volume control function and provides full volume audio to the speakers. The ATP-Series attenuators feature etched faceplate markings.
 
Features:
  - Adjusts loudspeaker output levels on 25 V and 70 V systems  
 Bypass function allows important and emergency announcements to be heard at the highest level even if local attenuator volume is set low or off  10 attenuation steps and an off setting  Attenuation in 3 dB increments except for two lowest settings, which provide 6 dB reduction increments  Mounts in standard electrical box, double (ATP35)  Convenient pluggable screw terminal connections  Speaker Types: 25 V and 70 V  Bypass Control: 9 V –30 V DC @ 22 mA max.  Power Rating: 35 Watts  Gang Box: Dual  Dimensions: 43⁄4"(W) × 43⁄4"(H) × 3"(D)  Shipping Weight: 2 Lbs.