US troops were issued language translation smart cards small enough to be carried in pocket. It typically would include translations of important keywords in languages of the region; as well visual illustrations to point out; and some cultural information that would help troops to interact with local population. Those can be useful in circumstances an attached interpreter is not available on a patrol.
U.S. Army Staff Sgt. Jeremy Torres-Cortes tries to speak with an Afghan villager by pointing to a phrase on his language translation card while patrolling Wadawu valley in Nuristan province, Afghanistan, Aug. 7, 2009. U.S. troops are issued the cards, which offer basic phrases in Afghanistan’s native languages. Torres-Cortes is assigned to 4th Infantry Division’s Headquarters Battery, 2nd Battalion, 77th Field Artillery Regiment, 4th Brigade Combat Team. August 2009. Source: https://www.defense.gov/Multimedia/Photos/igphoto/2001219234/
There are many varieties of those. I am always in search for more.
GWOT museum 