Summary
Back-Up Iron Sights (BUIS): Flip-Up Rear Iron Sights: This flip-up rear sight shall be designed to be affixed to standard CBP duty flat top M4 receivers with 1913 Picatinny rails. The sight shall be affixed to the rail via clamp and cross bolt, requiring a tool for installation and removal. The sight shall be equipped with a minimum of two apertures, a large aperture with an I.D. between .180” and .205” and a small aperture with an I.D. between .065” and .075”. The sight shall allow a no-tool change of apertures by the user. The sight shall be equipped with a windage adjustment feature. The windage adjustment shall require the use of a tool. Each adjustment of the windage shall provide audible and tactile feedback. Each adjustment shall be secure and provide 0.5 MOA. The height of the center of the apertures shall be 1.40” from the top of the Picatinny rail when in the flipped-up position. The height of the sight body shall be no more than .60” higher than the top of the Picatinny rail when in the flipped-down position. The sight shall be able to be flipped up by only swiveling the body of the sight upwards to a locked position. The sight shall remain in the locked position until a de-locking mechanism is pressed by the user. The body of the sight shall be made of hardened T6 aluminum. The remaining components may be constructed of hardened T6 aluminum or stainless steel. See attached file.