This is a simple infrared based music transmitter and receiver kit. There are two kits, one kit is the infrared music transmitter and the other is the infrared receiver with a basic LM386 based audio amplifier.
You keep the transmitter and the receiver in a line of sight and connect the transmitter to an audio source. The audio signal received by the transmitter module gets transmitted to the receiver via the infrared link.
It is one of the easiest electronics kits for electronics learners and beginners.