The product uses pulse width modulation to control the speed of DC brushed motors. When connecting power, ensure the positive and negative terminals are correctly wired to avoid damage to the speed controller. "+" indicates the positive terminal, and "-" indicates the negative terminal. DC brushed motors do not have fixed polarity; motor direction can be reversed by swapping the two connection wires. Compatible motors include 550, 775, 795, 895, and other two-wire DC brushed motors and DC geared motors. Product Name: Brushed DC Motor Speed Controller Model: MSDC-B PWM Frequency: 15KHz Working Voltage & Current: DC 12V-60V, 10A Output Power: Up to 600W (10A) Color: Black Material: Plastic Package Contents: 1 x DC Motor Speed Controller Note: Other items not included. Due to lighting effects and monitor settings, the actual color may vary slightly from images. Measurement may vary by +/- 1-3 cm.