Billiard ball straightness tester is used to check the flatness of the club for swimming pool , billiard ,snooker ,cue inspection.Used to check the straightness of the docking / shaft, roll the docking / shaft to see if there is any shaking.Important accessories for billiard cue repair, maintenance and maintenance. Lightweight and compact, easy to carry and use.Made of high-quality materials, it is durable and can be used for a long time.color:Black redMaterial:MetalPackage Contents:1 pair x calibrator1 x Storage BoxOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.