The Seagate Ironwolf is a 3.5-inch internal hard drive. With this duo pack you get two hard drives. The rotating vibration sensors in this hard drive reduce vibrations so that it lasts longer. This increases reliability and makes the Ironwolf suitable for 24-hour operation in 1 to 8 NAS servers. Due to the 256 megabyte cache memory, the hard drive often processes files faster than average. In addition, you receive 3 years of Seagate Rescue Data Recovery free of charge. The rescue service recovers the files in the event of damage. This gives you more certainty that your data will be saved.