A footbag is a small bean bag or san bag used as a ball in a number of sports and games. It is typically controlled by the feet, but in some sports every part of the body except the hands and arms may be used. The term footbag is also the generic name for the sports which use the footbag. The main varieties are freestyle footbag, footbag net, and circle kick. Both the footbag and the sports that use it are often referred to as hacky sack or hackey sack. (Note that Hacky Sack is a registered trademark of Wham-O, Inc. but the phrase is used to describe both their product and others.)