donnay formula octa tennis racketDonnay Formula 100 Octa, a superior tennis racket when it comes to playing feel, control and arm friendliness. Formula Octacore fits all levels of players from beginners to advanced players. This racket is very comfortable to play with and at the same time provides extra power and precision thanks to the six cores and Donnay's signature: the arm protection comfort. Product Info Head size: 100 inches Unstrung weight: 300 g Unstrung balance: 320 mm