Hokey is played on gravel, natural grass, sand-based or water-based artificial turf, with a small, hard ball approximately 73 mm (2.9 in) in diameter. The game is popular among both males and females in many parts of the world, particularly in Europe, Asia, Australia, New Zealand and South Africa. In most countries, the game is played between single-sex sides, although they can be mixed-sex. The governing body is the 126-member International Hockey Federation (FIH). One most interesting part to be know about Hockey Stick, It is a flat surface on the playing side and curved surface on the rear side. All sticks are right-handed – left-handed sticks are not permitted.