The speedsac indoor / outdoor by SKLZ is ideal for building explosive power. The speedsac is a very good solution to make training your leg muscles. Alteration to It is possible to make by mItem IDs of weight – bags to add or to take away. Speedsac the heavier and lighter The Speedsac is recommended not to use on concrete.
When speedsac includes: -Speedsac bag -Adjustable belt -Adjustable line -Three weight bags, each weighing 4.5 kilograms -Instruction DVD
SKLZ SpeedSac – Variable Weight Sprint Trainer