| Product Code | ISR4221-SEC/K9 |
| Aggregate Throughput | 35 Mbps to 75 Mbps |
| Total onboard WAN/LAN ports | 2 (10/100/1000Mbps) |
| RJ-45 ports | 2 |
| SFP ports | 1 |
| NIM slots | 2 |
| Memory | 4 GB DDR3 ECC DRAM |
| Flash Memory | 8 GB |
| Power Supply | External AC only |
| Rack Height | 1 RU |
| Dimensions | 1.72 x 12.7 x 10 in (43.7 x 322.6 x 254 mm) |
| Weight | 9.19 Kg |
| Hot Swapping | Supported |