Hanging outdoor lights

I want this.
My husband and I discovered a "rough diamond" at our home. It is located at the rooftop. Our house doesn't have a second storey but there is a small stairs that leads us to a flat squared area upstairs that are used to hang our washed clothes. Not large, but enough to gather some of our close friends for an outdoor dinner or to have a small garden with colorful plants on pots. Many ideas are still swirling in my mind and one of them is to first, decorate it with this lovely simple hanging lights. I don't know where I can find this but these lights will definitely add up the warm ambience of our home.

:)

Picture: http://brightjuly.blogspot.com/2012/09/diy-outdoor-string-lights.html