Handmade from leftover baseball glove leather. This is a training tool you can use at home. It helps you learn how to use your shoulders, elbows, and wrists, and strengthens your inner muscles. Diameter: 10cm Weight: Approximately 30g (There may be individual differences due to being made from leftover leather.) Color: The color of the front and back are different, but you cannot specify the color. Quantity: Sold and shipped as a set of 5. Shipping: Price includes shipping. Please note: These are handmade and hand-cut from leftover glove leather. There may be individual differences in color and texture, and unevenness on the cut surfaces. Please understand this before ordering. Also, we do not respond to inquiries about discounts.