This chamber is designed in conjunction with our cold molded acrylic and epoxy media. After encapsulating the sample, they are placed inside the chamber. By applying between 25 to 30 PSI during the cure time, the mounting compound is compressed down and around the sample, forcing air up to the surface. This process helps eliminate shrinkage and increase clarity and edge retention. Comes with an air hose. As an option an air pump tank is available. This Air Pump is designed for hand pumping pressure.