Double Looped – Much better as opposed to open looped extension springs, they consist of two coils at the end of the spring and are hooked up towards the eyebolt and pulley. They are really just a little more challenging to replace compared to the open looped springs if broken. http://bestgaragedoorcablerepair32455.bleepblogs.com/9940709/the-2-minute-rule-for-repair-dented-garage-door-panel