I have the whistle each for my wife and bought me not "stick" to each other to have while hiking in unfamiliar terrain. Anyone can now run his pace and I in between taking pictures alone. At intersections, the position now is necessary, "asked". In the forest the whistle seems obvious "quieter" than in urban terrain, where all around felt at 1 km radius ... ;-) proven on demos Of course it is very rarely used.
Visually, the whistle works with value and robust. It can be carried easily on a key ring. It is recommended that the way to read the instruction manual supplied explaining the correct Pfeiftechnik for really loud whistling (sic).
