Acme ® Thunderer Plastic 660 Whistle is the easiest to blow. You only have to breathe into this whistle to get a loud sound. Recommended for anyone who is short of breath, as a safety whistle for the young and elderly. What is more this whistle has refereed F.A. and World Cup Finals!! Its power and reliability is proven with sales of over 30 million.
Injection moulded plastic.
Non-stick pea whistle, high pitch, easily blown.
Blow Tone: 3600Hz.
Dimensions: 5(l) x 1.8(w) x 2(h) cm.
Preferred for soccer, rugby and coaching.