Here is a jump trainer that helps you build strength in your lower body muscles and improve your vertical jumps. It works on your calves, quads, and other muscles to help you perform better. You get an adjustable belt and ankle cuffs made from nylon that fit most body types. You also get 4 power tubes and 10 drill cards to get started.
The PER4M Jump Trainer gives you a good workout anywhere. Not too expensive either.