Purchase this at the same time when placing an order for a new controller with trim wheel only.
This is a Bourns 10 turn Potentiometer which will give a more realistic sensitivity to the elevator trim. The controller comes default with a 1 turn potentiometer (little less than 1 turn in reality) and I gear it 5 to 1, which gives approximately 4 complete turns of the trim wheel for end to end elevator trim adjustment. If you order this potentiometer with your controller order I will install this instead to give you 10 complete rotations of the trim wheel for elevator trim adjustments.