Abstract: A vibration proof device for strings or frame of a racket for sports in which it is possible to absorb vibration not only of the strings but also the frame without hindering operation, comprised of a block of rubber or plastic having a centrally located mushroom shaped vibrator integrally formed by punching or moulding, said block having a size that is substantially the same size as the width between strings and having longitudinal recesses in opposite sides for fitting between strings in use.