When a manufacturer post on their site and print on packing labels " use at your own risk" send it back. Drone World has some nice items and customer service is great. Bought some of the carbon fiber props for the Phantom 4 pro and today put $1700.00 in the trash. Props had about 2 hours of flight on them, drone was at hover mode at 200 feet and then back to earth in less that 5 seconds. One of the props just came apart from the hub area. No strikes or blows to these props. I like them at first and seemed to be a little more response to them but not worth the cost of your drone. Moral of this story.... Buy props that are made for your drone and not some other company that want stand behind them.