Detail
P528 28 in. Plug-End Extension Spring is a Holmes spring replacement for heavier 1-piece / tilt-up / canopy-style garage doors. Two P528 springs - one on each side of the door - can handle a 105 lbs. to 175 lbs. door, with an initial tension of 165 lbs. to 185 lbs. Four P528 springs - two on each of the door - can handle a 200 lbs. - 350 lbs. door. Either 4 c-hooks or 4 w-hooks (sold separately) are required to connect the springs to the jamb hardware. Material: Steel.
