5KU is a Taiwanese airsoft brand established in 2006.
They manufacture a wide range of upgrade parts and accessories for airsoft guns, including outer barrels, internal parts, and rail systems.
They are well-known for their external parts for AK, M4, and Hi-Capa series airsoft guns.

If you're looking for accessories to upgrade the look of your airsoft gun, be sure to check out 5KU!