Shepherd's whistle
They are also produced commercially. Simple whistles may cost less than 1 USD in bulk; expensive ones may be quite ornate. They are commonly made of plastic, aluminum, stainless steel, silver, brass, titanium, Corian, jade, buffalo horn and other materials.
W Dowler &amp; Sons
Dowler made several kinds of whistles, notably Beauforts & Cased Beauforts, as well as general service whistles (GSWs) and Porteous top GSWs. Dowler also made button whistles: escargot-type whistle with metal buttons or coins at the sides of the barrel. Though Dowler is mostly known such models, rare models attributed to him include the Hiat Registered Design of 1894: a combination of an escargot whistle with button sides and a beaufort with mouthpiece, sometimes referred to as Crest-top Beaufort.