1. Airmaster Propellers
2. APC Propellers
3. Avia Propeller
4. Collins Aerospace by Raytheon Technologies Corporation
5. DUC H?lices Propellers
6. General Electric Company
7. Hartzell Propeller Inc.
8. Hercules Propellers Ltd.
9. Hoffmann Propeller GmbH & Co.KG
10. Lockheed Martin Corporation
11. Mejzl?k Propellers s.r.o
12. MT-Propeller Entwicklung GmbH
13. Proptech Aero Ltd.
14. Sensenich Propeller Company
15. Textron Inc.
16. Titan Ring Designs
LLC
17. Turnegy Propulsion
18. Warp Drive Incorporated
19. WhirlWind Propellers
20. Yuanhang Propellers Manufacturing Co. Ltd.