Preserve uptime on supported HP server platforms with this 4 GB DDR3-1066 Registered ECC module from AddOn Networks. Built to match the 500660-B21 compatibility profile, it is designed for environments where memory integrity matters more than headline speed. Registered ECC helps reduce the risk of data corruption, while the DDR3-1066 data rate fits established infrastructure that still needs predictable, verified replacement parts. For IT teams maintaining older servers, the value is compatibility and control. This module is suited for refresh cycles, spare-part stocking, and targeted repairs where replacing an entire system is not justified. Factory-original compatibility helps simplify procurement and reduces the uncertainty that comes with generic substitutes. When the goal is to keep production systems running without introducing variables, this memory module delivers the right fit for the job.