A terminal block for transitioning electrical connections between two adjacent areas comprises at least one hole for receiving a stud. Each hole comprises a through hole and a sealing chamber surrounding the through hole. A stud is used for each hole. Each stud comprises a seal support flange and a sealing device. Each side of the seal support flange comprises a system for making an electrical connection. The seal support flange is sized to fit within the sealing chamber. The sealing device is located between the support flange and the sealing chamber. The stud is secured to the hole on the opposite side of the dielectric insert from the support flange and the sealing chamber to compress the sealing device between the support flange and the sealing chamber and cause the sealing device to fill the space of the sealing chamber and form a seal between the stud and the sealing chamber.