Mushkin Enhanced Essentials 4GB (2 x 2GB) 204-Pin DDR3 SO-DIMM DDR3 1066 (PC3 8500) Laptop Memory Model 996643 Cas Latency: 7 Timing: 7-7-7-20 Voltage: 1.5V Buffered/Registered: Unbuffered Multi-channel Kit: Dual Channel Kit Features: 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. Compatible Frequency This product is engineered to operate at the optimum frequency for compatibility with your system.