I needed this dual IR Flasher to expand my existing and extensive Niles IR repeater network. This dual flasher gives you two IR flashers from a single port. To confirm that your signals are being received, the transceivers will flash a small red light when they receive the signal. This allows you to know that your signals are arriving to each end of the receiver and are therefore being received by the unit you want to control. Simply put, the Niles dual IR are my go-to product and I highly recommend them without any reservation where you have a mission critical installation for remote control.