The ATH-CKR90iS in-ear headphones deliver amazingly clear Hi-Res Audio. In the unique push-pull system, the drivers face each other, but are wired out of phase, providing lower harmonic distortion and improved damping and bass frequency control. The use of drivers with different diameters improves high-frequency response. The strong yet lightweight machined aluminum housings reduce unwanted resonance, and their design positions the drivers for optimal performance, while ensuring a comfortable fit with excellent sound isolation. The performance is further enhanced by high-precision stabilizers that ensure linear diaphragm movement for faithful high-resolution audio reproduction.