> For the complete documentation index, see [llms.txt](https://docs.ceruleansonar.com/c/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.ceruleansonar.com/c/rov-locator/autosync-option-mk-ii-only.md).

# Autosync Option (Mk II Only)

Mk II Autosync uses GPS and/or GNSS signals to eliminate the need to calibrate the crystal oscillators and to manually sync the distance between units at mission start-up. "S" package systems ordered without autosync can be factory-upgraded to autosync at any time. Note that it is not possible to upgrade an obsolete "P" package system not originally supplied with autosync.