Billiard cue straightness detector

台球杆直度检测器，还需要自行购买4个608高速轴承、4个M4*24的螺丝、4个M4防脱螺母等，进行装配！For the billiard cue straightness detector, you also need to purchase 4 608 high-speed bearings, 4 M4*24 screws, 4 M4 anti-loosening nuts, etc. for assembly!