| Model |
SF-3990 |
SF-2500 |
| Memory |
128KB |
32KB |
| Display |
12 × 2 + 12 |
12 × 2 + 12 |
| Backlight |
- |
- |
| Data communications with a PC |
- |
- |
| Telephone directory (URL/e-mail address) |
 |
|
| Calendar |
- |
- |
| Schedule |
|
|
| Expense |
- |
- |
| Anniversary |
|
|
| Conversion (currency/metric) |
|
(currency) |
| Memo |
|
|
| To Do |
|
- |
| Clock |
|
|
| World time |
|
|
| Alarm |
|
|
| Calculator |
10-digit |
12-digit |
| Secret |
|
|
Multi-lingual messages
(6 languages for message displays) |
|
- |
Data exchange between two digital diary
units (optionally available SB-63 cable) |
- |
- |
| Power supply |
CR2032 × 2 |
CR2032 × 2 |
| Approximate battery life |
2 year*1 |
1 year*1 |
| Dimensions H × W × D (mm) |
 13.9
× 145 × 91
 10.3
× 145 × 178 |
14.7 × 136.5 × 83.5
10.8 × 136.5 × 162.5 |
| Approximate weight (g) |
120.0 |
110.0 |
