New futaba 9C
Hi lov2flyrc,
I'm no expert but the way I read the manual it lets you totally cut the engine and in Glider airplanes it retracts the prop for soaring. Then with one "bump" of a switch your back at whatever your last setting was on the throttle.
Here is a Quote direct for the manual on that function.
"The throttle trim benefits from JR's new one-touch™technology that allows a modeler to use the trim switch to shut down the engine, and then with just one "bump" of the switch back up, return it to its original setting."
Rick