Thanks, in asking "if FN makes the sight itself, does anyone know where they get the tritium inserts?"The tritium sights cannot be repaired so if the tritium insert falls-out you need to R&R (remove and replace) the sight. The tritium insert and/or broken/used tritium sights (service life of 10 yrs., some 20 yrs. rare) must be disposed of properly and not thrown in the trash as it is illegal. Tritium inserts cannot be purchased by the public as Tritium is radioactive.