The movement simulates natural walking movements, allowing the model to move forward smoothly. The compact design makes it easy to install in small models and enjoy the fun anytime, anywhere. Suitable for 3D printing characters or DIY projects, easy to customize. Made of environmentally friendly plastic, it is durable and in line with the concept of sustainable development. The design is sturdy and durable, and it can maintain good operation every time it is wound. Specifications: Due to different batches, there may be differences in product appearance and printed text, which will not affect use Colour: White Material: ABS Package Contents: 6 x Self-propelled movement Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.