The Stanley Hardware 730640 140 lb. Garage Door Extension Spring is manufactured from oil-tempered steel. The coil will fit most overhead sectional wood and steel garage doors. The garage door opener spring is double looped to add provided protection and safety. It is also tested for strength and is color coded in accordance with DASMA specifications. The garage door torsion spring is finished with a durable, powder-coated black enamel to provide years of use and comes with a safety cable.