Developing velocity in both pitching and hitting is an ongoing debate for years. For us here at Ground Force Sports, there is no debate...the Ground Force Sports Trainers are the most powerful tools available coaches and players can use to increase velocity and bat speed safely, quickly, and efficiently. Yes, that sounds pretty confident...but why do we stand behind this statement? Our theory is backed by science...and quite a bit of proof. Our products are used by 24 MLB clubs, countless high level coaches and players, and have proven results in every level of player from beginner to professional. The science is simple: the Ground Force Sports Trainers train the body to develop power from the legs (the strongest muscles), transfer the power into the hips, through the core, into and out of the arms. By utilizing ground force and leg drive, players create higher velocity and bat speed. We pride ourselves on deliver the best products on the market. We are pleased to hear the reviews around the globe calling the Ground Force Sports Trainers the best hitting and pitching tools ever made. Don't take our word for it get one yourself and use what the pros use.