The DD-RTS-FO Rapid Transition Sights were designed for competitions but are perfect for duty. The DD-RTS-FO attach directly to the host weapon's main picatinny rail and are positioned at a 45° angle. This allows the operator to use a magnified optic to engage targets at extended ranges and the DD-RTS-FO sights for targets at close range. The DD-RTS-FO sights can also be used as a back-up aiming system in the event the primary optic is fogged, damaged, or obstructed. Transitioning between the DD-RTS-FO and the primary optic is instant, and doesn't require the operator to remove a hand from the weapon or make manual adjustments. The DD-RTS-FO utilize the proven M16 style of sights, extending just 0.2" above the rail to keep the sight picture uncluttered and remove any chance of a shadow being casted into the optic. Additionally, the DD-RTS-FO features a high visibility fiber optic front sight and ships with interchangeable red, green, and yellow fiber optic tubes. Features of the DD-RTS-FO: Fiber optic front sight in red, green, or yellow (all included) allows for faster target acquisitionLow-profile sights extend only .2 inches above the top rail, don't interfere with primary optics or military IR illuminator /laser sight; same height above bore as standard-issue M4 / M16A4 sights1/2 MOA elevation and windage adjustmentsAmbidextrous sights easily and securely mount to Picatinny rails using a flathead screwdriverStill works if primary optic is fogged, damaged, or obstructedMachined from lightweight 7075 aluminum stock; Mil-Spec hard anodized for extreme durabilityFits MIL-STD-1913 rail-equipped AR-15 / M16-type riflesNote Dueck Defense Fiber Optic or Original Rapid Transition Sights are best for daylight useDurable construction for long service life Surefire Rapid Transition Sight with Red & Green Fiber Optics DD-RTS-FO