From a computer store that closed in 2003 and has been carefully stored since then. This memory was sealed in several separate bags for sale at the store. I did not test every single stick, but I did spot-check several of them using my CST SP3000 memory tester (which I also may be selling here eventually) to confirm that they checked out OK. I re-sealed them back into anti-static safe packaging. It's been a unique experience reviewing this inventory- like wading through a giant time capsule! If you are interested, please check out my other listings, including many items that are still in their original packaging. Thank you for stopping by. Have a great day!