Dell OptiPlex GX520 GX620 Desktop Series CPU Cooling Heatsink D7931 0D7931 CN-0D7931 R6852 0R6852 CN-0R6852.Dell Part Number: D7931 0D7931 CN-0D7931 R6852 0R6852 CN-0R6852Compatible Models: Dell OptiPlex GX520 GX620 Desktop Series