FOX40 Sharx Safety Whistle Yellow and Blue with Lanyard 8703-2208 The innovative FOX40 Sharx whistle! Very easy and comfortable to use, regardless of the weather (works both dry and wet). Specifically designed for use in a variety of weather conditions. This model emits a sound power of +120 dB. The whistle has two chambers and four sound resistors, making it much louder than its predecessors, the Fox Classic.