You are looking for an open-back HFI model? With the HFI-2400 goose skin feeling is assured. These open-back headphones with Ultra Low Emission (ULE-technology) offer airy & finest 3-dimensional sound reproduction. Specifically designed detachable velvet earpads will comfort your extensive listening hours. The HFI-2400 is the only Ultrasone HFI model with detachable cable. High class gold-plated drivers, placed according to the basic principle of the S-Logic technology, provide highest sound quality.