The dual force balance demonstration device is a desktop level experimental setup designed specifically for teaching basic mechanics in middle schools and universities. Through concise and intuitive operations, students can "see" and quantitatively verify the "conditions for an object to maintain balance under the action of two common point forces" within 3 minutes, thus gaining a profound understanding of the three elements of "equal magnitude, opposite direction, and collinearity". Typical experiment: Verify the balance condition of two forces: change the mass of the weight or the angle of the wire, observe that the LED arrow automatically aligns to 180 ° and the values are equal; Exploring the imbalance of "non collinear forces": Release the slide lock and demonstrate how force imbalance causes object movement.