Using the air tubes implanted in his palms, Zaku can control the ratio of air pressure and sound via chakra. By propelling this combination, he can release supersonic blasts of air. These blasts are powerful enough to destroy stone, and can also be used to soften the ground. By increasing air pressure to 100% and reducing sound waves to 0%, the blasts can be used to deflect thrown kunai.
The downside of this technique is that if the air tubes are clogged, the air that cannot escape would burst out from the sides, which can cause Zaku's arms to be destroyed inside out, to the point of being blown clean off.