Using the infrared remote control, students can see that it emits pulses of infrared radiation by pointing it at the infrared detector kit. The LED on the detector kit flashes when a button on the remote control is pressed. However the patterns of pulses are much too fast to distinguish by eye. To illustrate how different buttons on the remote control produced different patterns of pulses, students can use the infrared signal receiver kit. This consists of a PCB mounted on a box with a battery; different LEDs on the PCB flash on depending which button is pressed.