LaCie offers this spare drive and drawer for use with our 2big Quadra, 2big Triple, 2big Dual, 2big Network 1.1, 2big Network 2, and 2big NAS. The spare drive and drawer increases security in the unlikely event of a drive failure. You can immediately and easily hot-swap a failed drive. The capacity of your spare drive must be equal to or higher than the capacity of the drive being replaced. LaCie 2big 9000519 5TB Internal Hard Drive is one of many Internal Hard Drives available through Office Depot. Made by LaCie.