Hair Extension Toolkit expands the functionality of the standard particle hair system with advanced selection and editing tools. It introduces hair selections, which function similarly to vertex groups, allowing users to isolate guides and apply targeted operations like mirror, rekey, subdivide, or delete.

The toolset handles complex structural changes, including merging and splitting particle systems, resetting the number and steps of guides while preserving their original shape, and applying the visual influence of child particles directly to guiding curves. It includes dedicated pie menus for Particle Edit Mode and operators for converting standard curves into hair guides.