This is a tap made of PEI (polyetherimide) resin. It's a high-rebound, high-rigidity super engineering plastic, making it ideal for break cues and jump cues. One side has been surface-finished. ※Image 4 is an example of how it's installed. The shaft and ferrule are not included. If you would like to change the thickness or purchase two or more, we will create a separate listing page, so please inquire through the question box. Material: PEI (polyetherimide) Size: Diameter 16mm / Thickness 8mm Item...Accessories Type...Tap