Promotes proper grip, hand placement and swing path before, during and after contact. Teaches proper set up, grip and swing path. Instant feedback. Allows only the correct way to make contact with ball. Creates proper feel of staying inside the ball with rear elbow tucked in the slot. When sweet spot is struck flat against ball, proper palm up and palm down position has occurred. Shaft causes erratic ball flight when casting or sweeping occurs during swing. Shaft angle promotes hands in front of bat head and hands inside the ball. Shaft angle indicates when wrists roll during swing creating erratic ball flight. Handle aligns hands properly. Trigger on handle reminds hitter where hand should remain during swing. For top and bottom hand drills. Aircraft 6061 grade aluminum and stainless steel. Power coat painted shaft and sweet spot. High gloss clear coat. Injection molded polypro copolymer handle with comfortable polyolefin coating. For left and right handed hitters.