Silva Fox Whistle in Protective Case

The Boxed Silva Fox Whistle should be your go to Fox Whistle which when blown correctly omits 2 notes, the first a high pitched shrill which penetrates long distance can be heard for up to 2 ks away and the 2nd a harsh raspiness which adds panic and distress to the call when the sound of these  2 notes  combine they omit a distress call which Foxes just can not resist.

This shows how effective the "Silva Fox Whistle" is, when a fox wants to take it out of your mouth.

https://www.youtube.com/watch?v=QN1vtxS72CE