If any of you are wondering about the connectors used on the printed circuit boards (PCBs), these are known as Dupont connectors –
You can buy them in different sizes from single way (shown above) to ten way and above. If you search on your favourite auction site you will find many suppliers selling the connector housing, connectors and the crimp tools also. You can also crimp the connectors with a pair of pliers if you are careful.
There is a detailed article on this blog with lots more information.