The Noise Filter / Isolator is used to reduce or eliminate noise or attenuating devices that interferes with the transmission of UPB signals. Switching power supplies and other devices that run at frequencies between 4-40 kHz may interfere with UPB signals. The Noise Filter / Isolators are installed between the UPB device or Line and the noise or attenuating source. They block noise above 4 kHz and should be compatible with all power line technologies. They can also be used to block the attenuative effect of highly capacitive devices, such as Uninterruptible Power Supplies (UPS).