It can be used to connect ESC signal lines to control brushless motors or underwater thrusters for operation.
If the ESC of the thruster/motor supports bidirectional, then the speed knob can control the thruster/motor to rotate clockwise or counterclockwise. If the ESC of the thruster/motor supports only unidirectional, then it can only control one direction of rotation.
About points (lower right corner of the store page): ★5 points for every $1 spent; ★For every 100 points redeemed, you can get a $1.00 discount on the entire order; Applicable to orders of any amount.