Single-wide extension spring hardware box for 7-foot or 8-foot garage doors. includes the brackets, rollers, pulleys, hinges, cables, safety cables, and mounting hardware for a complete install or full rebuild. Nylon rollers and 14-gauge hinges in the box. Extension spring hardware is different from torsion hardware since extension setups use pulleys and safety cables that torsion systems do not. When your door runs on springs along the horizontal track on each side, This replacement part is the right kit. Torsion setups mount above the door and use drums instead. Pick your door height at checkout.