IR Links extend any IR remote control signal to another room. These links are used with various equipment / TV Links capable of plugging in an external IR emitter and receiver with a 3.5mm input / output.
IR Receiver (larger IR "eye") - Plugs into HDMI Extender Receiver. You will focus your IR Remote towards this receiver to operate equipment at the HDMI Transmitter side.
IR Emitter (small IR "eye") - Plugs directly into HDMI Extender Transmitter. If one source needs to be controlled focus it in front of source IR port. If multiple sources needs to be controlled install it in a way that the emitter has direct line of sight to all source IR ports.