WD Network NAS HDD 1 TB retail kit WD Network drives are specifically engineered for NAS systems with up to 5 drive bays. That means it's easy to seamlessly integrate these drives into your NAS system. They are designed & extensively tested for compatibility in the unique 24/7 operating environment & demanding system requirements of NAS systems for home & small business. The secret is in the technology. Advanced firmware technology built into every WD Network hard drive enables seamless integration, robust data protection & optimal performance for systems operating in NAS & RAID environments. Innovative technology reduces power consumption & lowers the operating temperature. The result is a more reliable & affordable solution for always-on 24/7 NAS systems. Your NAS system is always on. Therefore, a highly reliable drive is essential. With a 35% MTBF improvement over standard desktop drives, the WD Network drives are designed & manufactured to be a more reliable & robust solution for your NAS system. Our enhanced dual-plane balance control technology significantly improves the overall drive performance & reliability. Hard drives that are not properly balanced may cause excessive vibration & noise in a multi-drive system, reduce the hard drive life span, & degrade the performance over time.