These headphones are the first closed-back PRO headphones of Ultrasone with the new S-Logic® Plus technology. As all Ultrasone PRO headphones, the PRO 900i also comes with useful accessories. The PRO 900i ?s hard case is equipped with extra earpads with great isolation, detachable USC (ultra soft) cable and Neutrik connectors. The titanium-plated drivers guarantee unlimited precision in sound reproduction.