These barrels are reverse taper and adjustable from 64-68mm. The barrel is marked in quarter increments, which allows quick adjustments from 64 1/4 to 64 1/2 to 64 3/4 and so on! These are 3D printed with black carbon fiber. 
 **these are printed as they are ordered. Please allow two business days before we can print them. Also, these are designed to fit Buffet and Backun tenons. If you have a different instrument, reach out to us and we can talk about options so that I can print it for you in your size**
Instructions:
All the way down is 64 where the logo is aligned with the 1 marking. To get to 64 1/4, turn counterclockwise to the 1/4 mark, to get to 64 1/2 go to the 1/2 mark. Once you get all the way back around one full turn to the 1 marking again, you are at 65mm. At that point repeat the process.