Floorball is a type of floor hockey with five field players and a goalkeeper on each team. Men and women play indoors with 96–115.5 cm-long (37.8–45.5 in) sticks and a 22–23 cm-circumference (8.7–9.1 in) plastic ball with holes. Matches are played in three twenty-minute periods. The sport is relatively new and therefore evolving. The basic rules were established in 1979 when the first floorball club in the world, Sala IBK, was founded in Sweden. Official rules for matches were first written down in 1981.