Western Digital My Book Thunderbolt Duo 4TB 3.5 Thunderbolt Dual-drive Storage System Type: External Compatibility: Formatted for Mac OS X Snow Leopard or Lion operating systems. Compatibility may vary depending on user's hardware configuration and operating system. Operating Systems Supported: Mac OS X Snow Leopard or Lion Package Contents: Dual-drive storage system with Thunderbolt connector AC adapter Quick install guide (Thunderbolt cable must be purchased separately.)
