A-TECH 8GB KIT 2x 4GB Dell Inspiron 15 3520 15 3521 15R 5520 7520 SE 15z Ultrabook 5523 17R 5720 7720 SO-DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine Brand 8GB KIT (2 x 4GB) SO-DIMM DDR3 NON-ECC PC3-12800 1600MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Dell Inspiron. (See Compatibility List Below)