Brand new in box, still factory sealed. This will work in most modern laptops, including the new Macbook Pro.

G.SKILL 4GB 204-Pin DDR3 SO-DIMM DDR3 1333 (PC3 10600) Laptop Memory Model F3-10600CL9S-4GBSQ
Cas Latency: 9
Timing: 9-9-9-24
Voltage: 1.5V
ECC: No
Buffered/Registered: Unbuffered
Warranty: Lifetime limited

Please contact me with any questions.