The 9455S propellers have a brand new aerodynamic design giving the Phantom 4 series an impressive noise control performance. When used with the Phantom 4 Pro V2.0, up to 4dB (60%) of aircraft noise is lowered during takeoff and landing. Noise reduction is also enhanced when used with the Phantom 4 Pro, but not as much. <br> Specifications: Diameter ? Thread: 9.4 x 5.5 inch (24 ? 13.97 cm) <br> Weight: 11.7 g<br><br> Compatibility: Phantom 4 Pro V2.0<br> Phantom 4 Pro<br> Phantom 4 Advanced<br>Phantom 4<br><br> Package Include: Phantom 4 Seres 9455S Low-Noise Propeller Pair ? 2<br> Luckybird USB Reader ? 1