QNAP RAM-4GDR3L-SO-1600 4GB DDR3L RAM, 1600 MHz, SO-DIMM
QNAP 4GB DDR3L-1600 204Pin RAM Module for TS-251,TS-451, TS-651, TS-851, TS-253 Pro, TS-453 Pro, TS-453mini, TS-653 Pro, TS-853 Pro, TS-451U, TS-x53U, TS-563, TS-x63U, TVS-x63, IS-453S, TBS-453A, TS-251+, TS-451+
Note: Make sure all DIMMs meet the requirements for your NAS model (the information listed in product specifications).
When installing more than one DIMM, it is recommended to get the same type of memory (same size, same speed, same manufacturer) for each slot.