AddOn 16GB PC3-8500 DDR3-1066MHz ECC Registered CL7 240-Pin DIMM Quad Rank Memory Module. The AddOn 16GB PC3-8500 DDR3-1066MHz ECC Registered CL7 240-Pin DIMM Quad Rank Memory Module offers high-capacity and reliable performance for server environments. With ECC (Error-Correcting Code) support, it ensures data integrity and stability. Operating at 1066MHz and featuring CL7 latency, this quad-rank DIMM is designed for optimal server-level multitasking and demanding applications. Ideal for upgrading server memory or replacing existing modules, it enhances system responsiveness and efficiency.