This is a AmeriGlo Sight known as the Hackathorn, model SW-433B.
Employing a glare-reducing black serrated rear sight paired with a tritium ProGlo front sight" the Hackathorn Sights are designed for quicker front sight acquisition and maximized concentration on the front sight blade.
Features:
Green tritium .140 wide with orange outline front
Black serrated .150 wide square notch rear
Fits all S&W M&P except Shield
