The Synology HAS5310-20T is a 20TB hard drive designed for enterprise use. With a form factor of 3.5 inches and support for HDD drive types, this SAS interface hard drive offers reliable storage capacity for a variety of computing and networking needs. The unit quantity of 4 ensures that users have ample storage space for their data and applications. Ideal for businesses and individuals looking for high-performance storage solutions from a reputable brand like Synology.