This item was off the heazey. I could only grab rim but with the springbaks I could dunk! It gives you about 4 inches instantly! I would recommend this item for big ballas. 5 stars

I am a competitive volleyball player who has played for several years, and I just got these Speedsoles to try them out.

- They are very thin - you won't notice them much after you've put them in your shoes.
- They DO help you, just not by a lot. I think they gave me an extra inch or two of vertical jump. Don't believe the guy below who said that wearing the Speedsoles allowed him to dunk when he was only to touch rim before. That's a bunch of nonsense. The advertising also over-emphasizes the Speedsoles as some miracle equipment.

The Bottom Line: Get them if you want, but don't get your hopes up too high - they do help, but not by much. 4 stars

These soles do not increase your verticle, I tried them for a whole week, and on average there was absolutly no increase in my verticle jump. Im 5'11'' and can get my fingers over the rim, with these soles i could actually get a little less than that at first because there kindof slippery under the soles, which also caused extra stress on my joints.
They may improve running but i doubt it, its just extra weight. [...] 1 star

A very interesting product as I am a distance runner here at University of Hawaii @ Manoa. I feel quicker with the Springbak's in a sprint. But, towards the end of a long run I still feel fresh, and able to maintain a quick and efficient stride. 5 stars

First thing I noticed were my shoes coming off the track surface much faster with the Springbak's. You can feel the bounce immediately. They seem to increase my stride length as well as eliminate my shin splint problems which I have had for years. I am not sure about the increased vertical, but they give you much more balance and stability. Very happy with them, will definetly tell my team about the advantage I have gotten with Springbak Springsoles. 5 stars