Fine-tune the weight of your McDermott, Star or Lucky cue. Designed to fit most of McDermott, Star or Lucky cue models (please see the product specifications below). Use 1/4" Allen wrench (hex key) for installation (not included). Product Specifications: Bolt diameter: 1/2". Thread pitch: 2 mm. Threads per inch (TPI): 13. Price is for 1 bolt. Bolt length:· 0.5 oz: 1.9"· 1 oz: 1.2"· 1.5 oz: 1.9"· 2 oz: 2.6"· 2.5 oz: 3.3"· 3 oz: 4"· 3.5 oz: 4.8" · 4.0 oz: 5.5"