This is an original extension. This extension can be attached to custom cues and other manufacturers' cues. It can be used without modification, simply by removing the butt rubber and attaching it. Compatible with: Cognoscenti Jacoby Richard Chudy Lambros Adam etc. Cues that accept a 3/8-16 thread bolt can be used. ⚠️ Although it might be possible to attach to other cues if the bolt length is correct, please do so at your own risk. (Confirmed to fit my Cognoscenti cue) MEZZ extenders can be attached. Also, by attaching an X-Bumper, you can attach MEZZ extensions. Length: Approximately 1 inch Weight: Approximately 25.1g Bolt length: Approximately 3cm ⚠️ MEZZ's original butt rubber is not included. If you wish to purchase multiple items I am selling, please comment and I will discount the shipping cost. This is a handmade item, so please purchase if you don't mind minor imperfections. Please comment if you have any questions. I will try to respond as quickly as possible, but please understand if my response is delayed due to work or other circumstances.