I was looking to add some resistance to my plyometric training. I found this product and similar products at a local big chain sports store. I bought through Overstock.com because the price here was about 40% less than I found anywhere else. I recently incorporated this into my training, so I can't yet speak to results, but I'm very happy with this purchase. Only downside is there are no instructions or training programs included, but you can find workouts pretty easily on the internet including youtube.