The Ares Defense Shrike Advanced Weapon System, also known as the AWS, is an air-cooled, dual-feed light machine gun based on the AR-15 platform that fires the 5.56×45 mm NATO cartridge. It has the ability to be fed from either a magazine or a belt, similar to earlier versions of the Minimi/M249 SAW.
"Air-cooled dual-feed LMG is a performance upgrade kit for M16-type rifles and carbines."
— In-game description
The AWS is an LMG introduced in the 4: Naval Strike expansion. It is unlocked upon completion of the Swiss Cheese assignment. It has a high rate of fire, low recoil and average damage, with a capacity of 100+1 rounds.
Along with the other weapons of the first three expansions for Battlefield 4, the AWS actually has an in-game description, but it can only be viewed when the weapon is unlocked at the end of a round or if it is equipped in a gadget slot using external tools.