| Controller Type | Serial ATA |
| Country of Origin | Taiwan |
| Depth | 9.1" |
| Form Factor | Desktop |
| Height | 7.2" |
| Maximum Power Supply Wattage | 90 W |
| Memory Technology | DDR4 SDRAM |
| Network (RJ-45), RAID Supported | Yes |
| Number of 2.5" / 3.5" Bays, Number of Hard Drives Supported, Number of Solid State Drive Supported, Number of Total Expansion Bays | 4 |
| Number of Hard Drives Installed, Number of Solid State Drive Installed | 0 |
| Number of Network (RJ-45) Ports, Packaged Quantity | 1 |
| Number of USB 3.0 Ports, Total Number of USB Ports | 2 |
| Operating System | DiskStation Manager |
| Processor Core | Quad-core (4 Core) |
| Processor Manufacturer | Realtek |
| Processor Model | RTD1296 |
| Processor Speed | 1.40 GHz |
| Product Family, Product Line | DiskStation |
| Product Model | DS420j |
| Product Name | 4-Bay NAS DiskStation DS420j Diskless |
| Product Type | SAN/NAS Storage System |
| RAID Levels | 0, 1, 5, 6, 10, Basic, Hybrid RAID, JBOD |
| Standard Memory | 1 GB |
| Total Hard Drive Capacity Supported, Total Solid State Drive Capacity Supported | 64 TB |
| Width | 6.6" |