Factory replacement captive recoil spring assembly for the 9mm P226-X, and the wear part a high-round-count competition gun eventually needs.
Recoil springs are a service item, and a competition X-series gun eats them faster than a range gun does. This is the factory captive assembly, part 1204403-R, and replacing it on a schedule is cheaper than diagnosing the feeding and ejection problems a tired spring causes.
Fitment is unusually narrow even by P226 standards. The listing covers the 9mm P226-X and excludes both other P226 models and the P226-XCARRY, which takes a different assembly despite the shared X branding.
Note that this is a factory-weight replacement, not a tuning kit. There is no lighter or heavier option here; buying it is a decision to restore the gun to spec rather than to change how it cycles.
Add the SIG P226-X Recoil Spring Assembly to your build and see how it enhances your platform.