From video description:
This is a very early demo of an automatic bed leveling Z probe for Mini Kossel with modified Marlin firmware. The Z probe is an allen wrench that is automatically deployed and retracted. When deployed, it activates an Omron SS-5 micro switch on the end effector.
Documentation: http://reprap.org/wiki/Kossel
Project history: http://deltabot.tumblr.com
Here is a post about Mini Kossel printer itself:
http://diy3dprinting.blogspot.com/2013/12/mini-kossel-delta-configuration-diy-3d.html