HPE 691866-B21 is a 400 GB solid-state drive for enterprise server storage. It belongs to the Enterprise Mainstream range and carries the Mainstream Endurance classification, for use as a compact internal storage component in server environments.
The drive uses a SATA interface with transfer rates up to 6 Gb/s, also identified as SATA/600. Its 2.5-inch SFF format fits compatible HPE server configurations that require an internal SATA solid-state drive.
The HPE option part number is 691866-B21; the same drive is also listed under spare part number 692166-001 and model MK0400GCTZA. Its 400 GB capacity is intended for general enterprise storage, server data and applications where a compact SATA drive is required.