OBNXS1 Stuff 'n Things reviews the Feyachi Flip Up BUIS from Amazon, highlighting its lightweight yet durable aluminum construction with Mil-Spec hard anodization. The set is calibrated and designed for a low-profile rear sight on the same plane. It features a spring-loaded push button for quick deployment, windage-adjustable rear sight, and a micro-style windage knob offering the same MOA adjustment as a standard sight.