This is the current production model of the small ACME THUNDERER chrome-plated (nickel) finger grip whistle. Model # 477/60.5 This whistle has been around for a long time and is considered the best of the best. Tapered mouthpiece with a natural cork ball (pea). The 477/60.5 finger grip whistle has a waterproof speed pea. Easy to blow with instant response. The latest in high tech research and development creates the advanced modern Thunderer. Finger grip whistles were invented by ACME in the 1890s. ACME WHISTLES - MADE IN ENGLAND