RM-4ER0164	64GB DDR4 ECC RDIMM Module	ECC RDIMM RAM Module	$11,429	D4ER01-64G 64GB DDR4 ECC RDIMM Module Applied models SA6400
RM-4ER0132	32GB DDR4 ECC RDIMM Module	ECC RDIMM RAM Module	$6,939	D4ER01-32G 32GB DDR4 ECC RDIMM Module Applied models FS3410, HD6500, SA6400, SA3610, SA3410
RM-4ER2632	32GB DDR4-2666 ECC RDIMM Module	ECC RDIMM RAM Module	$5,819	D4RD-2666-32G 32GB DDR4-2666 ECC RDIMM Module Applied models FS6400, FS3600, FS3400, FS3017, FS2017, SA3600, SA3400, RS18017xs+ **It is required to use D4RD-2666-32G with identical memory modules of the same capacity and frequency.
RM-4ER0116	16GB DDR4 ECC RDIMM Module		$3,489	D4ER01-16G 16GB DDR4 ECC RDIMM Module Applied models FS3410, SA3610, SA3410 **Installing memory modules with differing capacities is not recommended. CLICK HERE for checking the Hardware Installation Guide of your Synology product for recommended memory configurations.
RM-4ER2616	16GB DDR4-2666 ECC RDIMM Module	ECC RDIMM RAM Module	$3,319	D4RD-2666-16G 16GB DDR4-2666 ECC RDIMM Module Applied models FS6400, FS3600, FS3400, SA3600, SA3400 **It is required to use D4RD-2666-16G with identical memory modules of the same capacity and frequency.
RM-4ED2616	16GB DDR4 ECC RAM Module	ECC RAM Module	$3,199	D4EC-2666-16G 16GB DDR4-2666 ECC unbuffered DIMM 288pin 1.2V Applied models UC3400, UC3200, SA3400D, SA3200D, RS4021xs+, RS4017xs+ (DSM6.2.3 or later), RS3621xs+, RS3621RPxs, RS3618xs, RS3617xs+, RS3617RPxs,  RS2821RP+, RS2818RP+, RS2421RP+, RS2421+, RS2418+, RS2418RP+, RS1619xs+ ** This RAM module does NOT compatible with the memory module preinstalled in RS2818RP+, RS2418+, RS2418RP+.
RM-4ED248G	8GB DDR4 ECC RAM Module	ECC RAM Module	$1,769	D4EC-2666-8GB 8GB DDR4-2666 ECC unbuffered DIMM 288pin 1.2V Applied models UC3400, UC3200, SA3400D, SA3200D, RS4017xs+, RS3621xs+, RS3621RPxs, RS3618xs, RS3617xs+, RS3617RPxs, RS2821RP+, RS2421RP+, RS2421+, RS1619xs+
RM-4EU0216	16GB DDR4 ECC RAM Module	ECC RAM Module	$2,778	D4EU02-16G 16GB DDR4 ECC Unbuffered DIMM Applied models RS2825RP+
RM-4EU028G	8GB DDR4 ECC RAM Module	ECC RAM Module	$1,389	D4EU02-8G 8GB DDR4 ECC Unbuffered DIMM Applied models RS2825RP+
RM-4EU0116	16GB DDR4 ECC RAM Module	ECC RAM Module	$3,759	D4EU01-16G 16GB DDR4 ECC Unbuffered DIMM Applied models RS2423+, RS2423RP+, FS2500
RM-4EU018G	8GB DDR4 ECC RAM Module	ECC RAM Module	$1,829	D4EU01-8G 8GB DDR4 ECC Unbuffered DIMM Applied models RS2423+, RS2423RP+, FS2500
RM-4EU014G	4GB DDR4 ECC RAM Module	ECC RAM Module	$809	D4EU01-4G 4GB DDR4 ECC Unbuffered DIMM Applied models RS2821RP+, RS2421RP+, RS2421+
RM-4ND264G	4GB DDR4-2666  non-ECC DIMM RAM Module	Non-ECC UDIMM RAM Module	$700	D4NE-2666-4G 4GB DDR4-2666 non-ECC unbuffered DIMM 288pin 1.2V Applied models RS2818RP+, RS2418RP+, RS2418+ ** This RAM module does NOT compatible with D4EC-2666-16G ECC UDIMM Module (RM-4ED2616), therefore two RAM modules CANNOT mixed use. **Minimum DSM version requirement: 6.2.2
RM-4ES0316	16GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$1,989	D4ES03-16G 16GB DDR4 ECC Unbuffered SODIMM Applied models DS1825+, DS1525+, DS925+, DS725+
RM-4ES0116	16GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$3,369	D4ES01-16G 16GB DDR4 ECC Unbuffered SODIMM Applied models RS822RP+, RS822+, DS3622xs+, DS2422+, DS1823xs+, DS1522+, DS923+, DS723+
RM-4ES2616	16GB DDR4 ECC SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$3,199	D4ECSO-2666-16G 16GB DDR4-2666 ECC unbuffered SO-DIMM 260pin 1.2V Applied models FS1018, RS1221RP+, RS1221+, DS3617xs, DS3018xs, DS2419+, DS1821+, DS1819+, DS1621xs+, DS1621+, DS1618+, RS820RP+, RS820+, DVA3221, DVA3219 ** This RAM module does NOT compatible with RAM module preinstalled in NAS. ***RS820+/RS820RP+ does not support the ECC feature, regardless of whether the expansion memory is ECC or non-ECC.
RM-4ES038G	8GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$1,159	D4ES03-8G 8GB DDR4 ECC Unbuffered SODIMM Applied models DS1825+, DS1525+, DS925+, DS725+
RM-4ES028G	8GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$1,719	D4ES02-8G 8GB DDR4 ECC Unbuffered SODIMM Applied models RS822RP+, RS822+, DS3622xs+, DS2422+, DS1823xs+, DS1522+, DS923+, DS723+
RM-4ES018G	8GB DDR4 ECC SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$1,669	D4ES01-8G 8GB DDR4 ECC Unbuffered SODIMM Applied models RS1221RP+, RS1221+, DS1821+, DS1621xs+, DS1621+
RM-4ES044G	4GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$709	D4ES04-4G 4GB DDR4 ECC Unbuffered SODIMM Applied models DS725+, DS925+
RM-4ES024G	4GB DDR4 ECC  SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$789	D4ES02-4G 4GB DDR4 ECC Unbuffered SODIMM Applied models RS822RP+, RS822+, DS2422+, DS923+, DS723+
RM-4ES014G	4GB DDR4 ECC SO-DIMM RAM Module	ECC SO-DIMM RAM Module	$769	D4ES01-4G 4GB DDR4 ECC Unbuffered SODIMM Applied models RS1221RP+, RS1221+, DS1821+, DS1621+
RM-4NS014G	4GB DDR4 non-ECC SO-DIMM RAM Module	Non-ECC SO-DIMM RAM Module	$719	D4NS01-4G 4GB non-ECC unbuffered SO-DIMM Applied models DS225+, DS425+
RM-4NS264G	4GB DDR4 non-ECC SO-DIMM RAM Module	Non-ECC SO-DIMM RAM Module	$719	D4NESO-2666-4G 4GB DDR4-2666 non-ECC unbuffered SO-DIMM 260pin 1.2V Applied models RS820RP+, RS820+, DS920+, DS720+, DS423+, DS420+, DS224+, DS220+, DS2419+, DS1819+, DVA3219, DS1618+ ** This RAM module does NOT compatible with ECC RAM module.
RM-E16D316	16GB ECC RAM Module	16GB (8GB X 2) ECC RAM Module	$3,199	RAMEC1600DDR3-8GB x 2 16GB (8GB X 2) ECC RAM Module Kit DDR3-1600 unbuffered ECC DIMM CL=11 Single Rank 240pin 1.5V Applied models DS3615xs, RS3617xs, RS18016xs+, RC18015xs+, RS3614xs+, RS3614xs/RS3614RPxs, RS10613xs+, RS3413xs+
RM-E16D34G	4GB ECC RAM Module	4GB (2GB X 2)  ECC RAM Module	$589	RAMEC1600DDR3-2GB x 2 4GB (2GB X 2) ECC RAM Module Kit DDR3-1600 unbuffered ECC DIMM CL=11 Single Rank 240pin 1.5V Applied models DS3615xs, RS3617xs, RS3614xs/RS3614RPxs
RM-16D38L	8GB (4GB x 2) DDR3L-1600 Kit	8GB (4GB X 2)  DDR3L RAM Module	$1,369	RAM1600DDR3L-4GBx2 8GB (4GB X 2) Non-ECC RAM Module Kit DDR3L-1600 unbuffered SO-DIMM 204pin CL=11 1.35V / 1.5V Applied models RS1219+, RS818+, RS818RP+, DS1517+, DS1817+
RM-18D3L4G	4GB DDR3L RAM Module	DDR3 RAM Module	$629	D3NS1866L-4G 4GB DDR3L-1866 Non-ECC RAM Module DDR3L-1866 unbuffered SO-DIMM 204pin 1.35V Applied models DS1019+, DS918+, DS718+, DS620slim, DS218+, DS418play