HyperX DDR2 features:

1.8 Volts operation, reducing power consumption by about 50 percent
Memory signal termination inside the memory chip ("On-Die Termination") to prevent reflected signal transmission errors.
Operational enhancements to increase memory performance, efficiency and timing margins.
CAS Latency: 5
Specifications

Memory Size 2048 MB
Designation PC2-8500
Memory Speed 1066 MHz
Pin Configuration 240
Memory Package DIMM
Memory Size (Total) 2 x 1024 MB = 2048 MB
Memory Type DDR2 SDRAM