As the worldwide leader in whistle technology, Fox 40 set out to develop a new whistle for the ever-changing demands in stadium and safety arenas worldwide. We looked at our bestselling whistles; the Fox 40 Classic and the Fox 40 Sonik Blast. The dependable piercing ultra high frequencies of the Classic's upper chambers penetrate crowd and background noise in any situation. The lower chamber of the Sonik Blast generates a powerful and penetrating lower frequency to carry over longer distances. Fuzing these two designs, along with the patented Fox 40 CMG comfort mouthgrip, finalized the whistle with a perfect sound and feel, creating optimal sound power.