Features: This billiard cue Strokes trainer is make of Glass and Acrylic materials, strong, enduring, and long terms use. Insert into the hole to support move back and forth to practice playing, convenient for aiming. Light in weight and compacts, portable and easy to carry, will not take up many space. It helps to improve the stability of your cue Strokes, making it essential training tool for both beginner and professional player. This billiard Strokes exerciser is widely applicable for various game such as nine balls, eight balls, snooker. Specifications: Materials: Glass and Acrylic Styles: Suitable for large head nine balls club/suitable for small head club Suitable for large head nine balls club styles balls diameter: about 6cm/2.36inch Suitable for large head nine balls club styles hole diameter: about 18mm/7.09inch suitable for small head club styles balls diameter: about 6cm/2.36inch suitable for small head club styles hole diameter: about 16mm/6.3inch Package Includes: 1Pc Billiard Strokes Trainer note: Please allow 1-2cm errors due to manual measurement, make surely that you not mind before order. Due to difference between different monitors, the picture may not reflect the actual color.