| General | |
| Manufacturer: | BenQ-Siemens |
| Model: | C81 |
| Platform: technological, no software |
S-Gold2 |
| Year: | 2006 |
| Capacity battery (MAh): | 820 |
| Measurements | |
| Dimensions (mm): (width x height x thickness) |
46.5 x 104 x 17.7 |
| Weight (g): | 90 |
| Processor | |
| Processor Type: | ARM926EJ-S |
| Clock Frequency (MHz): | 208 |
| Memory | |
| Random access memory (RAM) (MB): | 16 |
| Read-only memory (ROM) (MB): | 64 |
| Communications | |
| Phone: | GSM 1800, GSM 1900, GSM 900 |
| Bluetooth: | 1.2 |
| Other: | EDGE, GPRS |
| Multimedia | |
| Screen Size: | 1.8 |
| Screen Resolution (px): | 176 x 132 |
| Screen type: | TFT |
| Rear camera (Mp): | 1.3 |
| Speaker: | mono |
| Output of earphones: | company |
| Management and input | |
| Buttons: | navigation buttons, physical buttons, numerical keyboard |
| Extension | |
| Memory Cards: | MMC, RS-MMC |
| Additionally | |
| Operation time: (according to the manufacturer) |
Up to 300 hours of standby time; up to 5 hours of talk time |