The outer and inner surfaces have some wear like minor scratches and stains/residue. Working, can heat up and hold air pressure. The Kerr Injectomatic II wax injection machine is a specialized tool designed for jewelry mold making. As a product from the reputable brand Kerr, this machine is suitable for casting and various jewelry making processes. Its precise and efficient wax injection capabilities make it an essential tool for creating intricate and detailed jewelry molds. Whether for professional or hobbyist use, this machine is perfect for anyone looking to create high-quality jewelry pieces with expert craftsmanship.