Anodized Aluminum Plunger Tubes made by SFI. Please note: if purchasing the Caliburn Plunger Tube for a Caliburn, you will need the matching 3" spacer tube purchased separately for the rear section of the C4. It is also compatible with OG Caliburn and Caliburn-U through modified stock files.8" - Lynx7.31" - Caliburn5.72" - Talon Claw5.5" - Minx4" - Esper/Hypr3" - Caliburn Spacer Required Modified OG Caliburn File: https://www.thingiverse.com/thing:5272513Required Modified Caliburn-U Files: https://www.thingiverse.com/thing:5272511Lasering Option will take time to produce. If you select the option please email us at [email protected] with what you want lasered and the blaster the plunger tube is for. From there we will do a mock-up and send it your way for approval and then we will do a test run before the actual lasering to make sure everything looks good.