This product is either discontinued or we cannot get that from suppliers.
1GB DDR3 Ram Memory Module, 1 GB, DDR3 SDRAM, 1 x 1 GB, 1600 MHz, DDR3-1600/PC3L-12800, 204-pin, FF SoDIMM, Compatibility QNAP TS-x51 NAS Box.
The 1 GB 204-Pin SODIMM DDR3L RAM Module from Qnap is designed to run at 1600 MHz frequency. The 204-pin module is compatible with the TS-x51 series.