Product Description This sectional door extension spring has double loop ends for extra durability. It can replace most all spring configurations on residential doors that are no higher than 7 feet. Includes a 1/8 in. galvanized carbon steel aircraft cable that is installed From the Manufacturer This sectional door extension spring has double loop ends for extra durability. It can replace most all spring configurations on residential doors that are no higher than 7 feet. Includes a 1/8 in. galvanized carbon steel aircraft cable that is installed