HTLS (High-Temperature, Low-Sag) conductors have composite or carbon cores and require gentle handling. Stringing Machines 4.0 are the new smart pullers designed for HTLS. They use lightweight, modular designs and automated digital controls (sensors and real-time feedback) to manage the higher tension and delicate cores without damage. Features include IoT connectivity for live monitoring of tension/sag, and compatibility with advanced conductors like ACCR. This ensures safe, efficient stringing on existing towers to upgrade grid capacity without building new towers.