The Focusmaster Computer Interface allows the operation of your telescope focuser in conjunction with Tele Vue's Digital Indicator Kit and Focusmate Driver. It is the necessary link for computer readout. It requires the TVFocusPlus display/control software system in order to operate. Focusmaster is also compatible with ASCOM compliant focusing software through the use of plug-ins for third-party focusing software. It works with both Mac and PC. This device gets its power through the USB cable and does not need an extra power source. It comes complete with the USB cable to connect to your computer, the RS-232 port to connect the Digital Indicator, the RJ22 port to connect to Focusmate Driver to be fully operational.