The Power Bag develops explosive hitting mechanics and encourages lower body torque and stability. By giving visual feedback, the Power Bag helps hitters see what leads to more power at the contact position. The power bag can be hit and driven through, the better the mechanics, the more the bag moves. Hitters will find that using proper hitting mechanics and actually driving through the bag with the hips leads to the bag going all the way to the top or even all the way around. Features The Power Bag™ develops power hitting strength in the wrist and forearms.  Lance Berkman credits a similar device his father made with much of the power he has in his wrist and forearms. Hitting the ball with authority requires power and strength at contact which results in more spring off of the bat head. Bat speed is crucial for hitting the ball a long way, but if there is give in the wrist at contact much of the benefit of bat speed is lost. Strengthening the hands, wrist and forearms by using the Power Bag™ will decrease bat recoil and cause the ball to jump off of your bat. Is It Better Than a Tire? You bet it is! The Power Bag™ was specifically designed to allow the hitter to swing through the bag. A ball is in contact with a bat only 1/2000 of a second and some will have you believe any energy spent after contact is wasted. In theory this is correct, but how many times as a coach or parent have you noticed players of all ages give up on a swing? By teaching players to always finish their swing strong “completely” through the ball, you help them develop good habits that eventually translate into harder hit balls and sound muscle memory mechanics. Teaches Explosive Hitting Mechanics The Power Bag gives instant feedback with every swing. Common hitter faults such as poor hip rotation, casting or swinging around the ball, poor hand position (rolled wrist) , barring the lead arm or lunging at the target will result in a weak hit and the bag will not move much. If a hitter uses sound point of contact hitting mechanics as taught by most instructors, Bingo! The bag goes higher or all the way around. This visual and physical reward helps teach hitters how using good fundamentals leads to harder hit balls and helps the hitter develop the necessary strength to hit the ball with authority every time. What Is It Made Of, and What's In the Box? The Power Bag™ has a light foam center surrounded by a flexible, tear-resistant durable polyurethane coating. It is soft enough to absorb bat impact and can be used with most any bat. Each unit comes complete including the top arm and u-bolts which can be mounted to a pole 3½“ diameter or smaller. The top arm can also be mounted to a wood surface using wood screws or bolts. The unit can be removed from the top arm for storage by simply removing a ring pin. We recommend removing the bag from the outdoor elements when it will not be used for an extended period of time. Ordering Recommendations * Due to the process of the bags being made by hand, weight may vary by up to one pound. Large Power Bag - around 9.5 lbs - 10" diameter x 24" long.Players over 180 lbs. Large High school and college baseball. Medium Power Bag - around 7.5 lbs - 7" dia. x 24" long. Players 110-200 lbs. Small High School baseball programs and HS/college fastpitch. We have had several HS fastpitch coaches inform us that by the end of their first year using this bag, 4-6 of their girls were hitting this bag all the way around. None were able to do this at the beginning of the year. Junior Power Bag - around 5 lbs.- 7" dia. x 12" long. Most players 13 and under. 120 lbs and below. this bag is perfect for teaching the younger kids how good mechanics lead to more power.