Plastic Material The billiard ball rack is made of plastic material for durable use. Fitment:Fit for standard 2-1/4 Inner diameter size:The inner diameter size of the billiard ball holder is about 10.4 inch. Slightly Loose Design The slightly loose design makes it easy to install once the ball is set. REDUCE WEAR The reinforced rounded edges make moving the frame not easy and help reduce wear on your pool tablecloth. Packing list: 1 x billiard ball rack