The product is a lot of 12 desktop memory cards, consisting of a mix of 4GB and 8GB DDR4 and DDR3 modules. Each module has a capacity of 4GB, totaling 8GB per module or 8GB, totaling 16GB per module. The memory cards are specified to be ECC RAM, indicating error-correcting code memory for enhanced data integrity. The listing emphasizes that the memory cards are in good working condition, making them a reliable option for upgrading or replacing memory in desktop computers. Please review the label on each board shown. You are responsible to make sure that this is the memory that you can use and is compatible with your equipment.