I would like to find some of that "string" that is used on all of the USB Drives I have. I have also seen it used for draw cords with really small cord locks on some camping gear.

It is always black, very, very stiff, almost impossible to break and very, very small diameter. Feels almost like wire, but I'm pretty sure it is some kind of synthetic.

Also, would like to find some of those tiny cord locks used with the "string", whatever the real name for the stuff is.

Anybody know what it is and were I could obtain some? Without mortgaging the house to get it.