This is a beef esophagus (gullet) that has been stuffed with a mixture of ground beef esophagus and wheat flour, with a stretched beef bladder wrapped around. It looks kind of like a bully stick but it's a much softer treat.
Made of beef esophagus which has been split down the center and flattened into a strip. Averages 11-13 pieces per bag. The texture is similar to a firm jerky, and pieces can be folded and broken off of each strip.