This is 1045(10×4.5) SF Propellers Black. They are for lower RPM motor and slow flying drone models. They have wide and thin blades in their size category which makes them much flexible in crash conditions where they do not break easily. 1045(10×4.5) SF Propellers Black especially draws larger currents and in results will give you a considerable amount of thrust. 1045(10×4.5) SF Props have high-quality propellers specially designed for multi-copters. 1045(10×4.5) SF Props has 15° angle design in the end of the propeller to avoid whirlpool multi-copter flying.
