ECHO CALLS INC Ace In The Hole Ducks Pearl W/Black Mouth Piece Single Re. These calls produce a sound all their own that have been a favorite of guides and serious duck hunters for many years. These calls produce a barking quack that can be heard at extremely long distances. Specifications for ECHO CALLS INC 90023 Ace In The Hole Ducks Pearl W/Black Mouth Piece Single Re: Manufacturer: Echo Calls Color: Pearl w/Black Mouth Piece Fabric/Material: Acrylic Species: Duck ECHO CALLS INC 90023 Ace In The Hole Ducks Pearl W/Black Mouth Piece Single Re