Re: Photos of Petra Kvitova
She admitted it carelessly few years ago, when she and Vika promoted new Steam and Juice.
Vika in fact switched to Wilson Juice for real, from Head I think.
Of course, I'm not totally sure about new racket, but Steam was just a paintjob, it was discussed here few times also.
It would be absolutely stupid play last important tournament of the season with new type of racket.