This is a XS Sights Sight known as the F8, model SW-F027P-5.
Shoot better day and night. XS F8 night sights increase front sight focus by using a large" high-contrast front sight for fast sight acquisition. The wide notch rear sight easily aligns with the front sight and increases front sight visibility. XS F8 night sights give you the best notch and post solution for fast sight acquisition in all lighting conditions. Green tritium in front and rear glow in low light to aid in sight alignment. Highly visible orange ring is designed for maximum visibility in bright to low light levels" with photoluminescent particles absorbing ambient light to glow in low light. Base of notch in rear sight is rounded to draw focus to the top edge of the sights to aid in proper alignment. Rear sight overhangs back toward shooter to reflect glare down away from the shooter's eye. Rear sight ledge for one-handed slide manipulations. Fits in common holsters. Install by hand or sight pusher tool. Fits S&W M&P" M&P M2.0" M&P Compact" & M&P M2.0 Compact; 9mm" 40S&W" & 45ACP.
Features:
Green tritium with orange outline front
Green tritium rear