Description: Training Purpose: This pool training accessory is designed to improve the straightness and stability of your cue action in billiards, enhancing your overall performance in games like Snooker Material: Billiard cue action exerciser is made from PVC, this training equipment is reusable and built to long time to use Product Size: Pool Rod Trainer is suitable for cues with a diameter of 17 mm-18 mm, making it versatile for both large head cues and small head cues Package Includes: Each package comes with a cue action trainer, providing everything you need to start improving your game right away Easy to Use: Simply attach it to your cue stick and start practicing, it's an essential tool for both beginners learning the skills and experienced players wanting to refine their skills Specification: Material: PVC Size Chart: Suitable for 17 mm - 18 mm /0.67inch -0.71inch Large and Small Pool Cue Package Includes: 1Billiard Cue Action Exerciser Note: Please allow slightly errors 1-2cm differences due to manual measurement.