| Local Name | OT-S521A |
| Technology | GSM |
| 2G Bands | GSM 850 / 1900 |
| GPRS | Class 10 |
| EDGE | No |
| Announced | 2008. Released 2008 |
| Status | Discontinued |
| Dimensions | 103.5 x 44.9 x 10.9 mm (4.07 x 1.77 x 0.43 in) |
| Weight | 83 g (2.93 oz) |
| SIM | Mini-SIM |
| Display Type | STN |
| Screen Size | 1.8 inches (~21.9% screen-to-body ratio) |
| Resolution | 128 x 160 pixels (~114 ppi pixel density) |
| Card Slot | No |
| Phone Book | 800 entries |
| Call Records | 20 dialed, 20 received, 20 missed calls |
| Internal Memory | 2 MB |
| Primary Camera | VGA, 640 x 480 pixels |
| Video | No |
| Secondary Camera | No |
| Alert Types | Vibration; Polyphonic(64), MP3 ringtones |
| Loudspeaker | Yes |
| 3.5mm Jack | No |
| WLAN | No |
| Bluetooth | No |
| GPS | No |
| Radio | No |
| USB | miniUSB v2.0 |
| Messaging | SMS, MMS |
| Browser | WAP 2.0/xHTML |
| Games | 2 |
| Java | No |
| Features Summary | MP3/AAC+ player, Organizer, Voice memo, Predictive text input |
| Battery | Li-Ion 750 mAh battery |
| Stand By | Up to 400 h |
| Talk Time | Up to 10 h |
| Colors | Dark grey, Cherry red |
| SAR US | 1.15 W/kg (head) 1.17 W/kg (body) |
