This release does not have a Play Store Description, so we grabbed one from version 66.0.2:

Browser using the Gecko layout engine to render web pages, which implements current and anticipated web standards.

Fennec F-Droid is based on the latest Firefox release. It's focused on removing any proprietary bits found in official Mozilla's builds. There might still be some binaries left and the app (or some builds) might get removed or re-pushed anytime.

f-droid.org/packages/org.mozilla.fennec_fdroid/