Power Calls Spark African Blackwood Goose Call - This Big Bore Specklebelly Goose call is designed to have the full range and volume of a Specklebelly Goose while maintaining user-friendly operation with its built-in back pressure. The internal gut system includes a set of guts like no other! Hours of research and development as well as multiple 3D printed samples went into the design of this revolutionary internal system. The “Pan Style Gut” incorporates a shallow, but super wide tone channel so you can insure that every ounce of effort you put into this call will be transferred into sound. What you get as a result are loud ear-piercing yodels, soft clucks and murmurs with ease.