A transmission line connector for a contact set assembly for making contacts to contact elements of electrical devices, such as IC devices including DIPs and LCCs, affords a controlled impedance path between the contact elements of a device to be contacted and remote terminal ends of the respective transmission line conductors. The connector may be flexible or rigid. An actuating mechanism engages the connector adjacent the opposite end edges thereof for urging probe elements attached to the respective end terminals of the respective plurality of conductive lines into engagement with corresponding contact elements of the device to be contacted. A flexible transmission line connector permits rapid and continuous actuation of the actuating device between a normal disengaged position and an engaged position for making contact. The controlled impedance transmission line conductor is adaptable for providing contact to a wide range of device as to size and configuration, and as to number and location of contacts.