MATERIALS: Made of high quality resin SIZE: Diameter 57.2mm/2.25inch,weight 170g/6oz. Billiards cue ball is the standard size for American black eight billiards or snooker. FEATURES: The double sided design of the ball provides an unique playing experience, enabling you to hit differing points and thereby fine tune your targeting skills. Players can easily master the high, middle and low practice points, develop various lever methods quickly. MULTI-USE: Suitable for people with different needs at different stages; Fit for beginners and advanced players. Players tend to place their bets and control the standard line and dots of the ball.​It is also a great gift for your friends,family, billiards club member, or other billiards lovers. Package included: 1 Training ball + 1 Storage bag + 1 Instruction Manual