Two Macintosh computers share one serial device, or vice versa. It is fully-wired to support all Macintosh serial devices such as printers, modems & ISDN and is guaranteed up to 10,000 switching cycles. This manual switch has SureGrip with suction to provide stability during switching, metal case, heavy duty sealed rotary switch to prevent dust and moisture, gold-plated contacts and 5 Year Warranty. (Connectors: 3 Mini8 Female)