This product is designed for learning the skills of tracheotomy. It consists of housing, neck skin, neck muscles, trachea, thyroid cartilage, and simplified lung. We simulate the different skin layers with different materials so that you can feel the realistic tissue response when you palpate and make an incision. You can repeat several times of practices with one set of skin pad and trachea by adjusting their positions. So, with the 3ea replacement skin pads and 3ea tracheas, you can have multiple chances to operate the tracheotomy skills.