Check the listing for details. HC Cable RJ12 to USB PC Control Cable for SkyWatcher AZ-GTi SynScan 16ft. Condition: New. Listed at 23.99 USD. 16FT HC Upgrade Cable RJ12 to USB PC Control Cable for SkyWatcher AZ-GTi For onnecting PC/Laptop and the Skywatcher computerized Alt-Az tracking mount with RJ12 port, like AZ-GTi, to control Skywatcher Telescope. And for upgrading Skywatcher AZ-GTi. Support Windows Win7/8/10/XP, MAC iOS/Linux/Android. Windows 10 and Ubuntu-Mate 18.04 automatically identify the cable and register the serial port out of the box, no manual driver download needed.Compatible with ASCOM programs like PHD2 and AstroTortilla, with the EQMOD drivers in Windows (ASCOM) or Linux (INDI), with EQMOD, StellariumScope, and Stellarium, with AstroPhoto Tool program (APT). In order to use EQMOD, you may have to find the new port assigned by Windows, or use the search button on the EQMOD setup screen to find it for you. What you get: 1pcs x HC Upgrade Cable RJ12 to USB PC Control Cable for SkyWatcher AZ-GTi 16ft Please allow 1-2cm error for manual measurement.