9-way D-type data switch for use with serial devices such as mice & modems. The device is equipped with 9-way female D-type sockets. 9-way male-female serial cables are normally used to connect to computers 9-25 way male-male cables are used to connect to modems. Null-modem cables can be used to connect to other computers for direct cable communications. Available in 1-to-4 operation.