Mirror Bones & Weights is an add-on that mirrors armature bones and their associated vertex weights in a single operation. It adds a dedicated panel to the 3D viewport sidebar where users can specify the mirror direction. The tool relies on standard .L and .R naming conventions for bones and vertex groups, and includes an auto-naming function to append these suffixes. When executed in object mode, the add-on mirrors all vertex groups and weights matching the directional suffix on the selected object.