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