With this whistle, everyone will hear you! The FOX 40 is the most popular whistle in the world. Its loudness is 90 decibels, and its distinctive sound – slightly lower than the Classic model – dominates over street noise and in many other places. The Pearl model is a patented, two-chamber, ball-less whistle. This design ensures trouble-free operation in all conditions. Price for whistle only per piece. • Brand: Fox 40 Fox40 whistles are used by professional referees from the world's richest sports leagues and organizations, such as: NFL, NHL, NBA, FIFA, FIBA, NCAA and many, many others!