Frost Threaded Sleeves are available in 5 stock sizes:

1 - 0.381" shank end diameter (smallest)

2 - 0.383" shank end diameter

3 - 0.385" shank end diameter (stock shank size)

4 - 0.387" shank end diameter

5 - 0.389" shank end diameter (largest)

Custom sleeves of any size and/or to match your stock shank are the same price as stock  - contact for info and ordering custom sizes.

Frost Threaded Sleeve Modification

$45 - convert your mouthpiece or backbore to accept sleeves.  Contact here for custom work.