The quality BOGEN 35-Watt Attenuator AT35A control up to 35W of speakers. It allows local control of a group of speakers, without altering amplifier volume setting. This adjusts loudspeaker output levels on 25V and 70V systems. 

Features:

• 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  (ATP10/ATP35)
• 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 (AT10A/ATP10) or double (AT35A/ATP35)
• Convenient pluggable screw terminal connections (ATP10/ATP35)