3DR Iris+ Propeller set 3D Robotics IRIS+ Replacement Propeller Set Plastic T-Motor 9.5" Push-Pull Set IRIS+ features self-tightening, screw-on propellers for easy attachment. This set includes TWO propellers: one clockwise and one counterclockwise. One 9.5 x 4.5 T-Motor multirotor self-tightening counterclockwise propellers (with silver nut) One 9.5 x 4.5 T-Motor multirotor self-tightening clockwise (with black nut)