Bulk unit. ASUS DVD-E818AAT/BLK/B/GEN features a cutting-edge multimedia experience with quiet playback capability and 18X speed data transfer. It provides you with a quiet stable and high-performance multimedia environment. Features ASUS E-Green: automatically closes drive applications when not in use saving over 50% of power consumption. Quiet Track Delivery: E-Media provides a quiet usage environment AVRS Technology/The Best Usage Environment: AVRS technology reduces the vibration and noise during disc rotation and enhance the readability in order to create a quiet usage environment