As sibling poster [1] mentioned, the balls are cheaper (and probably last longer) than the tarp alternative. [1] https://news.ycombinator.com/item?id=10052777

As sibling poster [1] mentioned, the balls are cheaper (and probably last longer) than the tarp alternative. [1] https://news.ycombinator.com/item?id=10052777 https://news.ycombinator.com/item?id=10052777