I have a Squat Flex Vertical trainer you can google it if you want it is perfect. Daughter used it to get extra 2 inches before volleyball combine.
She got the scholarship now it is time for someone else to use. The item "Squatflex Squat Flex Vertical Jump Leg Strength Builder Basketball Volleyball" is in sale since Tuesday, January 19, 2016. This item is in the category "Sporting Goods\Team Sports\Basketball\Training Aids". The seller is "stuff2money" and is located in Tempe, Arizona.
This item can be shipped to United States, to Canada, to United Kingdom, to China, to Germany, to Japan, to France, to Australia.