Ideal for beginning players 8 and under playing on a 36′ tennis court, this lightweight foam ball has an oversized diameter for simple learning. Made of high-density lightweight foam for a modified bounce, the QST 36 Foam is perfect for indoor court settings. All Penn QST products are USTA and ITF approved and endorsed by the PTR. Penn QST 36 Foam 3-ball Polybag