Highlights self-tightening design keeps the propellers securely to each motor compatible with phantom 3 professional and phantom 3 advanced durable plastic construction provides both lightness and rigidity overview self-tightening design, simply rotate the propellers by hand to attach or detach. One pair of propellers: 1 clockwise and 1 counter-clockwise propeller. Basics: each propeller weighs 13g, diameter and screw pitch is 24×12.7Cm. Compatibility Compatible with phantom 3 professional and phantom 3 advanced.