This is an original extension. It's an extension that can be attached to custom cues and other manufacturers' cues. You can use it without modification, just by removing the butt rubber and attaching it. Compatible with cues from: Cognoscenti Jacoby Richard Chudy Lambros Adam etc. It can be attached to any cue that accepts a 3/8-16 thread bolt. ⚠️ If the bolt length is correct, it might be possible to attach it to other cues, but please do so at your own risk (confirmed to fit on a Cognoscenti cue). MEZZ extenders can be attached. Also, by attaching an X-Bumper, you can also attach a MEZZ extension. Length: Approximately 1 inch Weight: Approximately 25.7g Bolt length: Approximately 3cm ⚠️ The genuine MEZZ butt rubber is not included. If you wish to purchase multiple items I have listed, please leave a comment, and I will discount the shipping cost. This is handmade, so please purchase if you don't mind the minor details. If you have any questions, please comment. I will try to respond as quickly as possible, but please understand if there is a delay due to work or other circumstances.