Mushkin 971700A DDR3 ECC 4GB PC3-8500 ECC Apple OE 7-7-7-20 NONE 1.5V Compatible Frequency This product is engineered to operate at the optimum frequency for compatibility with your system. Compatible Timings This product is programmed to use timings that offer maximum compatibility with your system and original memory. Lifetime Warranty Quality guaranteed - we offer a lifetime warranty on this product and genuine, unmatched service and support. Type: DDR3 Voltage: 1.5V Speed Spec: PC3-8500 Frequency: 1066MHz Capacity Kit Type: Module Module Size: 4GB Timings tCL: 7 tRCD: 7 tRP: 7 tRAS: 20 Cooling Technology Heatsink: None