Easy-to-install replacement sights equipped with Meprolight's standard, tritium insert with visibility is guaranteed for five years. All sights fit in the factory sight bodies. No alteration to the rifle. AR-15 rear sights feature a 2-dot peep with tritium inserts, plus normal peep sight. Mfg: Meprolight SPECS: Steel sight body, blued. Tritium insert. Includes front and rear sight unless shown in chart. All are adjustable if barrel was originally equipped with factory adjustable sights.