Machined, full-length, stainless steel, guide rod replaces the factory, plastic part for smooth, dependable cycling. Use with the included, 11 lb., standard-weight, recoil spring, or the factory-original, dual, recoil springs. Included, firing pin return spring provides 20 – 25% extra power to quickly and positively return the firing pin to battery after ignition. Mfg: Wolff SPECS: Guide Rod – black, or natural polished finish. Kits include guide rod, 11 lb. recoil spring and extra power firing pin spring. Fits Colt Mustang and Pony .380 ACP.