Used, but in excellent working order and condition.  Pulled from working machine.  Fully mem-tested, no issues.  You are bidding on 2 8GB sticks of ram for a total of 16GB.

The SK Hynix HMA81GU6CJR8N-VK (often labeled as NO AC or N0 AC) is an 8GB DDR4 desktop memory module. It is an unbuffered non-ECC DIMM built for standard desktop computers.
Here is a quick breakdown of its specifications:
Capacity: 8GB
Memory Type: DDR4 SDRAM 
Speed: 2666 MHz (PC4-21300 / PC4-2666V)
Form Factor: 288-pin 
UDIMMRank/Organization: 1Rx8 (Single Rank)
Voltage: 1.2
VECC: Non-ECC
CAS Latency: CL 19