100% separation of front and back earcup cavity for maximum transient response and noise cancellation. They are designed the S4R 1.1 with as little leakage out as possible without compromising frequency response or comfort. A perfect combination of velour earpads, self-adjusting strap and balanced sound will enable you to work on headphones for hours. Pair stainless steel, nautical leather, velour, aluminum and wood and you are in for a treat. To extend durability and lifetime of cable connectors and to ensure the cable is not in the way of recording artists' performance. Every unit is individually tested and measured and comes with the frequency response measurements chart in the package. Every headphones's part can be purchased in Ollo store and replaced with home tools. Ollo Mission is offer customers the possibility of an upgrade when that's possible.