The FN509 now has access to one of the best night sights available from XS Sights.Texas based XS Sights has earned a reputation for producing some of the best combat pistol sights on the market. The company recently introduced the R3D 2.0  variant for Sig Sauer, Springfield Armory and the FN509. All of the R3D 2.0 features are present in their latest offering  resulting in a superb choice for FN’s pistol. Read my upcoming review.