SM-LED is an IR emitter led provided of a 1.8m cable ending with a 3.5mm jack.
It operates, in conjunction with the SM-EYE receiver, with a CAT5 Transmitter/Receiver pair and is usually connected to the CAT5 transmitter which is close to the source.
The SM-LED emitter needs to be placed so the light beam it emits hits the sensitive area of the source to be controlled.
Download here the available Hi-Res images of SM-LED.