The iMac 820-3126-A 21.5" A1311 Logic Board is a motherboard assembly specifically designed for the Mid 2011 iMac model. It features a 2.5 GHz Core i5 CPU with 4 cores and supports up to 16GB of DDR3 SDRAM memory. With its compact form factor and compatibility with Intel CPUs, this logic board is perfect for those looking to upgrade or replace the existing motherboard in their iMac computer. The Apple brand ensures quality and reliability in this essential computer component.