AFB-250 is designed to modulate radio signals from two receiving antenna to one optical Neutrik Duo APC output. Any passive or active antenna can be plugged in as it provides DC feed. DC feed are protected from short-circuits. A RF peak led indicate if RF field is too strong. A built-in 10dB RF attenuator can be activated on start up of device. With its rugged housing and 12V on XLR4 power, it is designed for location or live market.