vintage or reproduction Acme Thunderer whistle, likely a Model 58 or 60.5, made in England. The Acme Thunderer is an iconic pea whistle, first introduced in 1884, and is used by various sports and referees' associations worldwide. The Model 58 version is famous for being selected as the mates' whistle for the RMS Titanic. It is known for its powerful, long-range signaling and durable brass build, often nickel-plated. These whistles, especially vintage ones with a unique patina, are often sought after as collectibles.