This is a Beef Trachea that has been baked into a ball shape. Each piece is about 3-4" in diameter, and weighs about 2-3 ounces. There will be some variation in shape and size.

Trachea are a great natural source of glucosamine and chondroitin, two essential parts of maintaining joint health. 

Due to the slightly higher fat content, trachea balls are an extremely palatable chew for most dogs.