HK Mk23 Rear Sight Retaining Screw Features The HK Mk23 Rear Sight Retaining Screw is machined to HK s exacting tolerances ensuring a thread-perfect fit within the Mk23 s rear sight assembly that secures the sight without stripping loosening or backing out under the substantial recoil of the 45 ACP cartridge. As a factory HK component it matches the original specification precisely maintaining the rear sight s zero and structural integrity through thousands of rounds of sustained use. The black finish blends seamlessly with the Mk23 s existing hardware for a clean factory-correct appearance that aftermarket fasteners cannot replicate. A correct-fitting factory screw is critical to maintaining the Mk23 s renowned accuracy and this replacement ensures the rear sight stays locked in its intended position without play or movement between shots. Simple to install with standard tools it restores full rear sight security quickly and without the risk of improper fitment that comes with non-factory alternatives. For Mk23 owners who demand factory-correct components throughout their pistol this retaining screw is the only acceptable replacement. HK Mk23 Rear Sight Retaining Screw Specifications Manufacturer: Heckler and Koch Model: Mk23 Rear Sight Retaining Screw Color: Black Firearm Fit: HK Mk23