| Company name | Reg. code |
|---|---|
| FUSEN OÜ | 16980845 |
| FUSEE OÜ kustutatud | 14441558 |
| FUSSEN OÜ | 12326623 |
| FUSEC OÜ | 14786323 |
| FUSE ENGINEERING OÜ | 16107154 |
| FUSE ICSE OÜ | 16994758 |
| D-FUSE ELEKTER OÜ (former name D&R Drilling OÜ) | 16153160 |
| AUSEN OÜ kustutatud | 11089782 |
| AUSEN OÜ | 14823099 |
| FÜGEN OÜ (former name Asbestos OÜ) | 14983940 |
| UUSEN FINANCES OÜ | 16315496 |