Hillman 25 in. x 110 lb. Extension Spring w/Safety Cables White is designed to provide reliable support for your garage door by counterbalancing its weight as it operates. These extension springs are typically mounted along the sides of the garage door or above the horizontal tracks, stretching and contracting to ensure smooth door movement. Residential garage doors usually feature two extension springs, one on each side, while commercial doors often have multiple springs installed on each side for added strength. This package includes all necessary mounting hardware, detailed instructions, and important safety information to guide proper installation. Please note that incorrect installation or improper door positioning can lead to serious injury or death, so it is essential to follow all warnings and enclosed instructions carefully. Model Number: