SINGLE BULK PACK Western Digital Serial ATA 6Gb/s Black Power, 3.5" Internal Hard Drive 4TB, 7200 RPM. 64MB buffer. Our all new next-generation WD Black drives deliver improved performance that heightens the experience in your PC playground. These performance drives offer enhanced features over the previous generation to maximize system performance, allowing you to have more fun creating while spending less time waiting. Underlying it's athletic stance of performance and capacity, WD Black is smarter than the average drive with added vibration controlling technologies, an improved architectural design, an efficient dual processor and power loss protection technologies.