Upgrade the performance of your QNAP NAS or other compatible computer or server with this 8GB Kit. These came out of a QNAP TS-H686 file server. Each Apacer 78.B1GSB.4050B is a 512M x 72 DDR4 SDRAM ECC DIMM module. Each module consists of 9 pieces 512M x 8 bits DDR4 synchronous DRAMs in FBGA packages and a 4K Bits EEPROM, in a 288-pin dual in-line memory.Details and Features:

• Sold as a Set of 2 - 4GB RAM modules (78.B1GSB.4050B) with a total capacity of 8GB
  
• DDR4-2400
• UDIMM - Unbuffered DIMM Memory
• ECC - Supports Error Detection and Correction
• Rank - 1
• CAS latency - CL19
• Number of pins - 288

• Operating Voltage - 1.2V
• On-DIMM thermal sensor : Yes
  
• Bandwidth -21.3 GB/sec
• Speed Grade -2666 Mbps
  
• Max Frequency -1333 MHz
  
• Organization -512 words x 72 bits, 1 rank

NOTE: DDR4-2400 UDIMM memory modules have ECC and are Unbuffered. Please check your system configuration to ensure compatibility. Typically, UDIMM, RDIMM or LRDIMM modules cannot be mixed. Ensure your board supports ECC memory.