ECHO CALLS INC Timber Ducks Bourbon Double Reed Polycarbonate. These calls are made from a hard bullet proof plastic called PolyCarbonate.These calls are designed especially for close in calling. They are very easy to blow. Specifications for ECHO CALLS INC 77806 Timber Ducks Bourbon Double Reed Polycarbonate: Manufacturer: Echo Calls Color: Bourbon Fabric/Material: Polycarbonate Species: Duck ECHO CALLS INC 77806 Timber Ducks Bourbon Double Reed Polycarbonate