Acer Altos R520 M2, R720 M2, AcerAltos G540 M2, AcerAltos R520 M2 compatible Black Diamond memory 8GB DDR3 ECC Registered RDIMM 1333MHz. Compatible computer model: Acer Altos AcerAltos R520 M2, AcerAltos G540 M2, AcerAltos R720 M2, R520 M2, G540 M2, R720 M2. Black Diamond Memory offers the most extensive line of memory solutions today. With our decades of experience specializing in memory, Black Diamond Memory is a proven manufacturer to the semiconductor industry. Our great products combined with our world class service and support have helped us to where we are today. When you have an Black Diamond memory chip, you can count on it being the best available memory for your system. Our system specific Branded Memory line delivers in performance, and is designed to be guaranteed in compatibility with your system. Each of our memory chips come with a lifetime warranty for your peace of mind. Use our Upgrade Configurator to easily find the correct memory module for your system. Please keep in mind that this memory will ONLY work on the models listed above. 15% Restocking fee will apply for non-defective items.