How to use this trim tool

Hi
Can someone explain me the use and how to use this trim tool (see image)
Thanks

That's the dynamic trim tool. It's for trimming by playback, either realtime or faster/slower than realtime. I've never really gotten the hang of it. Plus, I feel like your machine needs to be very responsive for it to be useful; millisecond delays are more pronounced when you're trying to hit edits like you're playing Guitar Hero.

The instructions are in the "Dynamic Trimming (or 'JKL Trimming')" Section of the manual. In the March 2020 version, it starts on page 707.

If memory serves, it isn't any more functional than the regular tools, it just does the same stuff in a different way. I.e., it slips, slides, ripples and rolls, just like you'd do with a mouse.

Thank you