Product details:

Oil tempered black coated torsion springs include winding and anchor cones pre-installed. Springs are factory coated black for smoother, cleaner operation. For use on doors with 4" standard lift drums. Engineered for maximum application range. Springs are made of steel coils with aluminum cones. - Life cycle - Minimum 10,000 cycles, at +/- 7.5 lbs of target door weight. Includes: 1 3/4" ID Torsion spring with winding and anchor cone installed - Features: Engineered for maximum application range. - Minimum 10,000 cycles, at +/- 7.5lbs of target door weight.