The Gaia Hand 20 from Stella Robot is an open-source five-fingered dexterous hand with 16 active and 4 passive degrees of freedom (20 total), featuring a biomimetic thumb structure and underactuated finger design. It uses a modular joint architecture with independently actuated modules per finger, mimicking human hand degrees of freedom. All hardware design files, electronics, and software are open-sourced under the MIT License. It provides a standard UART communication interface, uses off-the-shelf brushless motors with 3D-printed structural parts, supports Python SDK, and launched at 9,998 RMB.