Hi RoyR,

The reason for the TREV is to allow you to reverse the direction of your Trim on your Throttle so that it will work at the bottom half of your stick instead of the top half. This will change it on all models. The Reverse function changes the direction of the specific servo action but not the trim action.

I hope you find this information helpful. You can also reach our Futaba support team at 217-398-8970 opt 2, or via fax at 217-398-7721.

Sincerely,
Krysta Hunt
Product Development & Support Specialist
Futaba Service Center USA