As far as whistles go these are a bit of a classic and are about as good as they get.
Nickel plated brass, non stick pea whistle with tapered mouthpiece to produce high pitch, 20g, 4.5cm long, preferred for soccer, rugby and coaching. £2.67 with free delivery and possible 5% Quidco.
Big deep sound, far carrying, some consider more user friendly.
Recommended for: Coaching, Football
Blowrate: Most effort
Blowsound: High Loudness