This Dutch sport is similar to netball and is played with either all girl teams or co-ed teams with four men and four women. The objective of this game is to throw a ball through a bottomless basket that is mounted on a large pole.
The official equipment rules for the ball are stated below:
1.5 Ball
Korfball is played with a round number 5 ball of a type that has been approved by the IKF. The ball shall be at least two-coloured. Its circumference should be 68.0 – 70.5 cm and the weight of the ball must be in the range 445 g to 475 g inclusive. The ball must be inflated to the prescribed pressure indicated on it so that when it is dropped onto the playing surface from a height of about 1.80 m, measured from the bottom of the ball, it should rebound to a height, measured to the top of the ball, of between 1.10 m and 1.30 m. A coloured outer casing is understood to be a ball on which a pattern is printed in a color other than the basic colour of the ball. This pattern must be so symmetrical that the ball, whilst turning, does not lose the visual effect of actually being round.
References:
The Rules of Korfball – http://www.ikf.org/wp-content/uploads/2013/01/Complete-Rules-of-Korfball-from-2012-07-01-rev.pdf
Photo – http://www.leedsuniversityunion.org.uk/groups/korfball/