We use the machined original prototype master to make an precise RTV (room temperature vulcanization) mold with silicon materials. And then the mold cavity is filled with PU (polyurethane) plastics through vacuum casting facility. By manipulating the vulcanization the vulcanization temperature, every kind of plastic work in different properties can be produced and satisfy the need to have a small quantities in a short time. The major advantages for such a tooling method is its simplicity, low cost, and short lead time. It brings a lot of benefits from speed, quality and quantity respects.