The d is d300 not only stands for distance it defines it the next generation of flx face technology allow for 76 of the face to be completely free from the body delivering maximum bend upon impact and a powerful launch with visible technology around the entire face the power holes filled with te031 urethane allow the face to flex upon impact for improved feel with a crisp pure recognizable sound for distance and accuracyflx face technologythe ground breaking flx face technology minimiz