The ThumbPRO Performance Baseball Thumb Guard gives a proper bat grip, quicker bat contact through the zone, and helps prevent bat sting. ThumbPRO's ergonomic design keeps the sport thumb guard perfectly and comfortably in place on the hand. Avoid the "Death Grip!"
We suggest using a string or ribbon to measure around the circumference of the thumb--halfway between the base and the first knuckle of the thumb.
We recommend measuring for size in the way it will be used up at bat. If the players wears a glove at bat, measure with the glove on. If a glove is not worn, then measure without a glove on.