Yin and Yang represent complementary opposing forces that interact and perpetuate each other, forming a dynamic, balanced system where the whole is greater than the sum of its parts. This timeless worldview of harmony became the primary inspiration and guiding vision for the project. The core intention was to translate this philosophy into a functional everyday object. Two circles joined by a clean horizontal bar embody perfect balance: the solid circle functions as the pivotal shaft for smooth door operation, while the open ring adds visual lightness. Through rigorous 3D modelling and PLA prototypes, the design achieves a harmonious balance between utility and beauty.