The 444 models have a handle, a shaft, a glider (that the ball rides on) and a stop. When you swing. the glider slides up the shaft, hits the stop (clicking sound) and the ball takes flight. The 444 model size 30 is a -9, the 28 is a -12 Example: If the bat is 30” long it will weigh 21 oz. If you want a special order call 877-395-2287 We feel that it would be good to call us regarding the 28" -12 as to how the player might respond to the bat. This product will teach the hitter about his/her release point and contact point with an emphasis on the hands taking an inside approach to the ball and you lag the barrel of the bat until it releases it-self. With the visual, instant feedback you will learn the feel to hit the ball where you want. See Video on web for other drills.