Attenuator with Bypass for 25V/70V Speaker Line. Adjusts loudspeaker output levels on 25V and 70V 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. 2 models control up to 10-watt and 35-watt speaker systems. 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, single (ATP10) or double (ATP35). Convenient pluggable screw terminal connections.