Dagger Defense (A Veteran owned company) offers its tactial BUIS backup iron sights for use on standard picatinny rail mounts. A must have accessory for your picatinny rail systems. Has spring loaded, button activated flip up function to give you the extra advantage. ATTENTION: The push button on the sights doubles as the spring loaded retention knob. You can turn the push button clockwise/counterclockwise to ensure the sights stay in the (down) locked position with the proper tension. Use in combination with red dots, holographic sights and scopes. Made of aluminum alloy in a black matte finish. A great accessory for your tactical items.