A-TECH 8GB KIT 2x 4GB Dell XPS 14z 15 15z L511z 17 L701X L702X 3D L401X L421X L501X L502X L701X L702X SO-DIMM DDR3 NON-ECC PC3-10600 1333MHz RAM Memory Genuine Brand 8GB KIT (2 x 4GB) SO-DIMM DDR3 NON-ECC PC3-10600 1333MHz RAM Memory Genuine A-Tech Memory Lifetime Warranty Toll Free Technical Support 1-866-557-4527 Designed For Dell XPS. (See Compatibility List Below)