Up for sale is a set of 4 used 4GB Samsung DIMMs (4GB 2Rx4 PC3L-10600R-09-10-E1-P1), for a total capacity of 16GB.  These are registered ECC DIMMs typically used in servers.  You can look up "Samsung M393B5170FH0-YH9" for exact specifications.  Please observe ESD precautions when installing.  Shipping only to the 48 contiguous states.