| # | Name | Location | Applications |
|---|---|---|---|
| 1. | QES PRESSURE CONTROL LLC | 🇺🇸 Oklahoma City, OK, United States | 1 |
| 2. | Qest Communications International Inc. | 🇺🇸 Denver, CO, United States | 1 |
| 3. | QEST GROUP LIMITED, | Macau, Macau | 2 |
| 4. | Qest Quantenelektronische Systeme GmbH | 🇩🇪 Holzgerlingen, Germany | 1 |
| 5. | Qest Quantenelektronische Systeme GmbH | 🇩🇪 Reutlingen, Germany | 1 |
| 6. | Qest Quantenelektronische Systeme Tubingen GmbH | 🇩🇪 Boblingen, Germany | 1 |