- Suitable for physical mechanics and student group experiments. - Construction and components: metal base plate, metal support rod, two single rollers and two-row double rollers. Includes 2 cords with hooks (one 100 cm and one 68 cm). The arrangement shows that moving the pulley can save about half the effort, but cannot change the direction of the force. - Fixed pulley operation: hang a fixed roller on the bracket, attach the rope, hook one end to the hook and the other end to the dynamometer. Pull the dynamometer at a constant speed and observe that the display corresponds to the weight of the hook. This demonstrates that the fixed pulley is not labour-saving, but the direction of use can be changed. - Use scenarios: 1) Classroom physics lab: compare movable versus fixed pulley configurations to observe mechanical advantage; use the dynamometer readings to quantify effort and load. 2) Group experiments: explore force transmission, rope length effects, and different configurations using the 100 cm and 68 cm cords. 3) Demonstrations of direction change: redirect pulling force with a fixed pulley while keeping the load constant, illustrating practical applications in lifting tasks.