Pool balls are used to play various pool (pocket billiards or pool billiards) games, such as eight-ball, nine-ball and one-pocket. In North America, they are sometimes referred to simply as "billiard balls" (except among carom players). These balls, used the most widely throughout the world, are considerably smaller than carom billiards balls, slightly larger than British-style pool balls and substantially larger than those for snooker. According to WPA/BCA equipment specifications, the weight may be from 5.5 to 6.0 oz (160–170 g) with a diameter of 2.250 in (57.2 mm), plus or minus 0.005 in (0.127 mm).[11][12] These are often referred to as 2 1/4-inch (57 mm) balls. The balls are numbered and colored as in the table.