Wench style duck calls have the patented ?Tone Ridges? and ?Tuning Ditches? on the sounding board which keep the reeds from sticking or freezing while giving the call its raspy highs and lows. The patented reed relocation system lets you take the call apart for cleaning and put it back together correctly every time. The internal parts are molded from graphite the ideal sound conductor giving the WenchA(R) its unique pitch and range of tones.Features: One of the duckiest duck calls Good for any calling situation from open water to green timber U.S. Patent Nos. 5910039 & 6234859