These rotor blades will bring a new sense of style to your drone. The typhoon propellers have been designed to be the most efficient and silent injection molded propellers on the market. Their built in locking hub makes installation easy. Simply twist on the a propellers in a counter clockwise motion and the b propellers in a clockwise motion. They make a great replacement to swap out your current propellers, or a backup in case they get damaged. Bundle includes 1 Set of A and 1 set of B propellers and O-rings for your Yuneec typhoon quadcopter drone. Compatible with the following quadcopter typhoon drones: Q500, q500+, q500 4k, and g.