This is a version of the plastic clip that is used to tension ropes for camping, tarps, etc. This is not a unique design, they all look basically the same.I printed on the Low settings on Makerware (0.34 layer height) with 50% infill (18mins to print). I only started using it today so not sure if I will need to up the infill % or even how long the PLA will handle being out in the open but appears to be working well so far. If you need a tensioner for a larger rope I would assume you should be able to simply scale it up to suit. If someone dose scale it up let me know how it went.