An extension to USB includes an insulative tongue portion and a number of contacts held in the insulative tongue portion. The contacts have four conductive contacts and two pairs of differential contacts for transferring differential signals. The four conductive contacts consist of a power contact, a ground contact, a − data contact and a + data contact. One pair of the differential contacts is located between the power contact and the − data contact and the other pair of the differential contacts is located between the power contact and the + data contact. The four conductive contacts are for USB protocol and arrangement of the four conductive contacts with the insulative tongue portion is compatible to the standard USB connector. The two pairs of differential contacts are for non-USB protocol. The extension to USB is capable of mated with a commentary standard USB connector and a commentary extension to USB, alternatively.