Axiom 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1066 (PC3 8500) Desktop Memory Model AX31066N7S/4GK Voltage: 1.5V Buffered/Registered: Unbuffered Features: Top grade chips and components - Each Axiom memory module is manufactured to meet or exceed OEM specifications. Fully tested - All memory modules that leave our warehouse are fully tested to guarantee quality and reliability. Guaranteed compatibility - Axiom guarantees that each system specific module will work with its corresponding OEM computer. Free unlimited tech support - Speak to a real human being and not a computer message. Tech support is available to every one of our customers via phone or email.