Mushkin 976609A DDR2 FBDIMM (2x4GB) 8GB PC2-6400 FB Mac Pro Apple OE 5-5-5-18 MAC PRO FB 1.8V 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. Dual Channel Kit Engineered for dual-channel architecture. Lifetime Warranty Quality guaranteed - we offer a lifetime warranty on this product and genuine, unmatched service and support. Type: DDR2 FBDIMM Voltage: 1.8V Speed Spec: PC2-6400 Frequency: 800MHz Capacity Kit Type: Dual Kit Module Size: 4GB Timings tCL: 5 tRCD: 5 tRP: 5 tRAS: 18 Cooling Technology Heatsink: Mac Pro