The Dudley Thunder SX used slow pitch softballs are 12 inches in size, made of composite leather material with red or blue seam stitching. They are designed for league play and have a compression hardness of 300, with a CORE of 0.52. These optic yellow softballs are suitable for USA Softball association and are ideal for slowpitch ball players looking for high-quality balls for their game. Made in China, this set of 12 balls from Dudley is perfect for enhancing your team's performance on the field.