Keep compatible Buffalo NAS systems running with a purpose-built 4 TB replacement hard drive. The OP-HD4.0BST-3Y is designed for select TeraStation 1200D and 1400D families, plus LinkStation 220D and 420D families, giving IT teams a straightforward path to restore failed capacity without introducing mismatched media into the enclosure. For infrastructure teams, the value is in fit and continuity. A replacement drive matched to the supported platform reduces guesswork during service events and helps preserve the intended storage configuration. That matters when the goal is to recover capacity quickly, maintain predictable operation, and avoid the cost and delay of broader system changes. This drive is a practical choice for environments that depend on Buffalo NAS hardware for shared storage, backup targets, or departmental file services. When a drive needs to be replaced, a compatible part keeps the system aligned with the original design and helps minimize disruption to users and scheduled jobs. Choose this model when you need a direct replacement path for supported Buffalo systems and want to keep recovery simple, controlled, and consistent with the platform already in place.