The cascade system's microprocessor control system with 3 separate interior doors that can be opened independently. Minimize frost accumulation in the room. The unique door seal design minimizes the temperature loss when the door is opened. The stainless steel internal handle ensures that the door can be easily opened even in the case of frost. High quality door gasket 5 gasket, 4 sealing ring for door, 1 inner door seal to provide maximum protection against heat intrusion. The sample port on the back makes temperature monitoring convenient.