Premium-quality replacement for old, tired factory recoil springs in the 1911 Commander improves function and reliability. Constant rate design along the entire length to help keep the slide closed longer when shooting heavy loads. Reduces wear from battering and shortens the distance spent casings are ejected. High tensile strength, round wire, spring steel ensures years of reliable service. 18 lb. is the correct, factory weight and an excellent choice for restoring your pistol to its original specs. 20 lb. Extra power spring holds the slide closed a little longer to help solve the problem of brass ejecting too far (more than 15 feet). SPECS: Round-wire spring steel. Approximately 5-1?8' (13cm) long uncompressed. Fits Commander-length 1911 pistols.