Our custom hand-finished stainless steel tightbore 6.01mm inner barrel from our own brand XT Airsoft. 

- Enlarged hop window (6mm long and 4.5mm wide), designed for hop rubbers with larger contact patches.
- Hand finished with polished hop window, crown and both ends of the internal surface to remove imperfections.
- Fully cleaned.
- Internal polishing Ra 0.5.  (In comparison ZCI is around Ra 1.0 and stock brass inner barrels Ra 1.5).
- 30 day no-quibble returns policy should you wish to return.

Please note: 
- Barrels have "6.02mm" laser etched, however they're closer to 6.02mm
- Please ensure you use quality BB's, e.g. no seams, 5.95mm
- Clean after every game day (I recommend doing this for any inner barrel).