Feature: 1. It is made of high quality fiber material, and long lasting. 2. The outer diameter of the interface is 13mm/0.5in, and the inner diameter of the interface is 8mm/0.3in. 3. Compact, portable and lightweight. Nice replacement for pool tube, it is an ideal and helpful tool accessory. 4. Size are 1 inch/25mm 0.8 inch/18mm, 0.5 inch/12.3mm for your choice. 5. Easy to apply to rod head, only need to screw on. Easy to use. Spec: Item Type: Billiard Cue Stick Ferrules Material: Fiber Color: As Pictures Shown Outer Interface Diameter: Approx. 13mm/0.5in Inner Interface Diameter: Approx. 8mm/0.3in. Package List: 40 xBilliard Cue Stick Ferrules Note: Please check the detailed size on the picture.