Incorporate this plastic training ball into your baseball practice for soft-toss and batting drills with its heavy-duty perforated design. It"s thick wall structure is durable without leaving marks on walls when used indoors. Available at a great price so you can stock up. * Includes 1 dozen. Seamless, perforated plastic baseball has thicker wall structure for increased durability. Great for soft-toss drills indoors and outdoors or batting off tees in gym. Will not mar or leave marks on gym walls