See below for color codes for the jumper cables. Of note, the maximum voltage going to the receiver (the longer device) cannot exceed 3.3V, whereas voltage can be up to 5V for the transmitter (the shorter device). Since it is hard to visualize the transmitter labels, from top to bottom it reads: Voltage | Data | Ground | Antenna. Make sure the large metal portions of the transmitter and receiver are clearly visible without an obstructed line-of-sight (this is important!). Of note, the Raspberry Pi 2 and 3 GPIO headers are the same. Lastly, if you would like to use different GPIO pins than the ones listed for the data cables, please see the Miscellaneous page under the Further Customization section for more details.