This trainer is designed for learning and practicing intramuscular injection skills on the buttock. It has epidermis, dermis, fat, and muscle layers. The structure is anatomically accurate. We simulate the different skin layers with different materials so that you can feel the realistic tissue response and resistance when you puncture the skin layers to the fat and finally muscle layer. It has a drainage hole at the bottom, the liquid will come out and the model will dry naturally. It has high durability to provide multiple times of use.