J.C. Conners Taos Lighting Springs are the best on the market. Double torsion springs are wound from music wire and will outlast any other 4-coil kit. The spring pin is made from high tensile strength steel and will not bend like so many others. A sturdy lock with nut and bolt are included to prevent spring loss. Each kit is made for a specific trap so it fits and does the job you expect.
In your comment code, could you please state the make, model, and high or low lever to send you the right kit.