https://gunsbuyerusa.com/product/ar-15-hk-style-micro-sight-set/
Troy Industries Sights, used by HK on MR556 rifles. Great fit for any Rifle or Pistol platform that has a higher Picatinny height than an AR-15, such as the BRN-180
https://gunsbuyerusa.com/product-category/parts/
Rugged, flip-up sights provide failsafe backup when your primary optic or red dot sight fails. Sight body flips up easily when you need it and locks securely in place under powerful spring pressure and two locking detent balls, so it can’t be accidentally bumped down until you hit the spring-loaded button on the left side of the base to retract it. Base clamps securely to any military or commercial Picatinny rail using a standard flathead screwdriver. No protruding knobs or levers to catch on brush, clothing, or other equipment. Sturdy, protective “ears” shield posts and apertures from impact. Rear sights bolt to flattop receiver rail and are only .460" high when folded. Detent-locking adjustment wheel lets you change the windage setting in ½ MOA increments. Front sights clamp to handguard accessory rail and are only ½" high when folded. All models have M4-type post that’s elevation adjustable in ½ MOA increments.
https://gunsbuyerusa.com/product/ar-15-hk-style-micro-sight-set/
SPECS: Rear - Stainless steel and aluminum, Black or Dark Earth finish. Rear Sights – All models 1.17” (3cm) long, 1.25” (3.2cm) wide, 1.85” (4.7cm) high extended. 1.8 oz. (52g) wt. Front - Stainless steel and aluminum, Black or Dark Earth finish. HK-Style Front – 1.17” long, 1.25” wide, 1.9” (4.9cm) high extended. 1.6 oz. (45g) weight. M4/M16-Style Front – 1.17” long, 1.25” wide, 1.75” (4.5cm) high extended. 1.6 oz. weight.