R86 -IR refers to the potentiometer speed control switch drive. The Potentiometer can regulate the rotation speed of the motor and switch speed at any time. Control Mode: IN1 and IN2 are connected to the starting and reversing signals, ENA connected to the potentiometer speed controller. Signal Level: The Switch is 3.3 to 24 v effective. Specification of potentiometer : 10 -100 Kohms.