The Leybold Trivac B series pumps have rotatable intake and exhaust ports. These ports can be oriented horizontal or vertical and are attached with four socket head cap screws. An O-ring below the port seals it to the pump body. We sell these ports, 1 inlet or 1 outlet (sold as 1 each) as replacements. They are made of cast aluminum and are sometimes broken by accident. These DN16, KF16 exhaust and intake replacements fit the D4B and D8B Leybold Trivac vacuum pumps. Leybold part number ES43171253.