This product is either discontinued or we cannot get that from suppliers.
Qnap Long-dIMM Ram Module RAM-8GDR3-LD-160, 8 GB, DDR3 SDRAM, Speed 1600 MHz, Server, FF DIMM.
The 8GB DDR3-1600MHz Long-DIMM RAM Module from Qnap is designed for use with TS-870U-RP, TS-879U-RP, TS-1270U-RP, TS-1279U-RP, and TS-1679U-RP NAS servers.