| # | Name | Location | Applications |
|---|---|---|---|
| 1. | Hreaeus Quarzglas GmbH & Co. KG | 🇩🇪 Hanau, Germany | 1 |
| 2. | HREEWAY TECHNOLOGY CO., LTD | 🇰🇷 Seoul, South Korea | 1 |
| 3. | HREIN ENERGY INC. | 🇯🇵 HOKKAIDO, Japan | 1 |
| 4. | Hrein Energy, Inc. | 🇯🇵 Sapporo-shi, Japan | 1 |
| 5. | HREIN ENERGY, INC. | 🇯🇵 Sapporo-shi, Hokkaido, Japan | 1 |