Hynix 16GB Dual Channel Kit 2 x 8 GB 204 pin DDR3-1600 SO-DIMM (1600Mhz, PC3-12800, CL11, 1.35V, for Apple and notebook) (Personal Computers)
Bought have 16GB RAM for Macbook Pro 13-inch (2012). The change was simple. Screw the bottom plate with PicoFinish Phillips Schraubendreher.261 PF PH 00x4 solved. 16 GB were detected without problems, though Apple says only a maximum of 8GB are allow