Synology 4TB HAT3300 Plus Series SATA III 3.5" Internal NAS HDD: From the manufacturerReliable hard drives for Synology systems3.5" SATA HDDSynology Plus Series SATA HDDs are designed to meet the reliability, endurance, and performance requirements of 24/7 storage in Synology small and medium-sized business storage systems.These durable NAS hard drives have