HGST Travelstar 2.5 Inch 500GB 7200 RPM SATA II 16 MB Cache Internal Hard Drive (0S02858) Built in Hitachi's halogen-free production environment Patent-pending technologies add reliability in non-stop computing environments More unplugged computing time to keep you working at peak performance no matter where you are - in the office or on the road Internal 2.5 hard drive for your laptop Delivers the perfect balance of capacity, ruggedness and low power consumption Internal 2.5 hard drive for your laptop More unplugged computing time to keep you working at peak performance no matter where you are - in the office or on the road Delivers the perfect balance of capacity, ruggedness and low power consumption Patent-pending technologies add reliability in non-stop computing environments Built in Hitachi's halogen-free production environment The bare drive part number is 0J26005 and the drive inside the kit 0S02858