Genuine ACME whistle. Made by specialists with over 150 years of experience. Made in the United Kingdom. The Acme No. 58.5 Thunderer Whistle is a classic Acme Thunderer Referees Whistle, designed to stand out from background noise. A small pea whistle with a taper mouthpiece. It is made from solid brass, with a silvery finish. Silver Plated, Gold Plated and Rose Gold finishes packaged in a Presentation Box.