I'm having a hard time figuring it out. . I guess this is the creator showing how its done but what is going on with the lanyard here? A more detailed picture of similar or other working systems would be helpfull. . .
http://www.youtube.com/watch?v=7XD6rGpAY8Y
http://www.youtube.com/watch?v=7XD6rGpAY8Y