Montgomery Gentry are encouraging fans to send letters to U.S. troops overseas. The country duo have teamed up with Coca-Cola's new energy drink, Vault, for its 'Honoring the Uniform: Calling for Support' program. Pre-addressed postcards can be found on special Vault 12-packs at participating stores and online at and People are encouraged to write letters of support on these postcards, and then drop them in the mail. The postcards will all be sent to a USO collection center and then distributed to troops during the holiday season.

"We're honored to join in the effort to support our U.S. troops, and it's an exciting start to our partnership with Vault," reports Eddie Montgomery. "As USO entertainment tour veterans, we know this program is a great way to spread goodwill and offer thanks to the brave men and women serving our country in the U.S. and around the world."

The program also aims to raise up to $100,000 for the USO.