Unity Tactical FAST, Red Dot Riser, Elevates Lower 1/3 Mount to 2.26 Optical Height, Direct to Picitinny, Anodized Finish, Black FST-ORB FAST is a series of optic mounts and platforms that provide end users with a quicker sight picture than standard height mounts. A 2.26" optical centerline height provides faster/easier reticle acquisition while wearing electronic EarPro/communications headsets, night vision goggles and gas masks and allows for more rapid visual processing of the battlefield by promoting a heads-up posture.