The dog tag is more than 100 years old, and this little piece of metal connects us to those slain defenders.

The U.S. military’s use of metal dog tags dates back to 1906, according to history website armydogtags.com.

18 Cool Things Metal Gear Solid 2 Doesn’t Outright Tell You Steal dog tags, lean and peek around corners, stop guards from calling in reinforcements, and more ...