N-Type Test Port Extension Cables (set of 2) (75 Ohm) The Agilent (now Keysight) 11857B are N-Type Test Port Extension Cables and includes two precision 24 inch cables, phase matched to 2 degrees at 1.3 GHz. One cable has 75 ohm type-N male connectors on both ends, the other has one type-N male and one type-N female connector. Option B24 deletes phase requirement between cables in the set.