A-05 is a pre-embedded steel plate base weighing 504.8g, which plays a vital role in the installation process of chair armrests. It is specially designed for chair armrest installation, and its weight gives it sufficient stability. This base adopts a two-hole design. These two holes are the key elements of the entire installation process. They can be accurately connected with other components such as the handrail column, making the cooperation between the components more stable and tight. As a pre-embedded component, it needs to be placed in a suitable position in advance. When the handrail is installed later, it is positioned and fixed through these two holes, providing solid support for the handrail, ensuring that the handrail can withstand external forces without deformation during long-term use, ensuring the safety of the user.