The Acme Tornado 636 is a little bundle of sound with a size that belies its volume. The Tornado 636 has plenty of shrill power packed into its slimline form. Acme Tornado 636 whistles only take a reasonable effort to blow and when you do the 636 rewards you with a high tone. With it is compact size and high tone, the Tornado 636 is popular amongst ramblers and mountain rescue but is just as happy in the sports arena. At Clubline Football, we think the Acme Tornado 636 is a slim superstar of a whistle that offers a lot, considering its dinky dimensions.