The AK-12U is the carbine variant of the AK-12 assault rifle.
It is an unlockable carbine in Battlefield 4, and is referred to as AKU-12.
The AKU-12 acts very similarly to the AK-12 assault rifle, having less range and accuracy, but having greater hip fire accuracy. It also has a unique feature in which burst fire yields a higher RPM. The recoil is also extremely low, with the gun gently pulling to the right.