A table tennis ball is a small, lightweight sphere used in the sport of table tennis, also known as ping pong. It is typically made of plastic and has a diameter of 40 millimeters. The ball weighs 2.7 grams and is designed to bounce well on a table tennis table. The surface of a table tennis ball is smooth, allowing it to travel quickly through the air. It is usually white or orange, making it easy to see during play. Players use paddles, or table tennis rackets, to hit the ball back and forth over a net, aiming to score points against their opponent.