GM20537-2 is a motor drive controller module made by Wodeyijia, a Chinese electronics company. It is a two-phase stepper motor controller, with a maximum current of 8A and voltage of 44V. Its features include adjustable maximum output current, PWM speed control, and 3-stage speed control (low speed, medium speed, and high speed). It has a built-in control logic and can be used to control various types of motors. This module is used in applications such as robotics, CNC machines, and medical equipment.