If you are using babolat, look to see if there is a circle of wavy plastic around the racket frame. This is babolat's patented technology. Also, check to see if there are babolat letters on the frame of the racket head. If you really can’t see the formed logo, you can also weigh it on an electronic scale. It is 300g without adding a line when shooting without a line. If you add a line, it will be between 315 and 320.