Ernie Parker's Wrist Snapper
Ernie Parker developed The Wrist Snapper training device to teach his students the importance of a proper wrist snap at the pitching release point and to help strengthen the wrist and forearm.  This training tool focuses specifically on that part of the release which can present some frustrating problems for the fastpitch player,  the snap.  This product addresses the problems of weak and incorrect snaps for both underhand and overhand pitching or throwing.  The device is great for other sports such as baseball or tennis where a strong wrist snap can help to produce additional power and movement.  When the wrist snap is performed properly, the device produces a distinct sound that is both heard and felt, providing instant feedback.  If the wrist snap has a twisting motion or is not snapped hard enough, no distinctive sound is produced.  With this tool, the player gets both positive and negative feedback instantly.  During the process of shaping the snap correctly and receiving positive feedback, muscle-memory builds and strength builds as well.  All of these come together to improved the shape and strength of the wrist snap.