This is an original extension. It's an extension that can be attached to custom cues and other manufacturers' cues. It can be used without modification, just by removing the butt rubber and attaching it. Compatible with: Cognoscenti Jacoby Richard Chudy Lambros Adam etc. It can be attached to any cue that uses a 3/8-16 thread bolt. ⚠️ If the bolt length is correct, it may be possible to attach it to other cues, but please do so at your own risk (confirmed to fit my Cognoscenti). MEZZ extenders can be attached. Also, by attaching an X-bumper, you can also attach MEZZ extensions. Length: Approximately 1 inch Weight: Approximately 25.5g Bolt length: Approximately 3cm ⚠️ MEZZ's genuine butt rubber is not included. If you wish to purchase multiple items I have listed, please comment and I will discount the shipping cost. This is handmade, so please purchase if you don't mind minor imperfections. If you have any questions, please comment. I will try to reply as quickly as possible, but please understand if there is a delay due to work or other circumstances.