Braco's Floating Ball is a 15-inch sphere that appears to float in midair. According to a description, a performer can walk away from the ball, which is completely controllable and it does not require strings.
For a performer to demonstrate that this is an actual floating ball, the manufacturer suggests removing the ball from a chest, moving it about and then returning it to the chest. The ball is then removed and dropped on the floor, making an audible sound to prove that it is heavy.
Finding out the secret to a magic trick is itself tricky, as there is no magic without the secret. However, since there are online balloon refills for this item, Braco's Floating Ball is most likely a balloon-supported trick. In the chest trick, the balloon is lowered into the chest and swapped with an identical ball that is heavy, giving the viewer the illusion that a heavy ball can float.