Reply to Midi Fighter Button Socket

I've been working on making an arduino based Midi Fighter like device. While i could solder all the buttons in, I really like the sockets i see in the pictures on the midi fighter. So that the buttons just get pushed into the holes, and they sit on the bottom and make the connection. As i don't have a Midi Fighter I can't see what exactly is acting as the socket to make the connection. If someone could either post close up picks, or if anyone knows exactly what they are and how i can replicate them that would be awesome!



Thanks