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.