As long as it is a Balfour or R Johns ring, there is a lifetime guarantee on sizing.

Send it to:
Balfour
ATTN: Repair Dept
7211 Circle S Rd
Austin TX 78745

Put the size it needs to be, a phone number and your return address in with the rings.

Contact Skip Witttich from Balfour Baltimore office for new orders
http://www.militaryrings.us/coinfo/contact.html
1-800-996-8636