Gun Pro has teamed up with TROY  to offer their Delta 1 Sights® on our popular 45 Degree Offset BattleSights. Requiring little or no visual and mental estimation, Delta 1 sight posts deliver lightning fast, precise alignment. Designed with the 3-gunner in mind, Delta 1 Sights offer a faster and more natural target acquisition when transitioning from rifle to pistol (when equipped on both firearms).
U.S. PATENT #8,863,433