HK VP9 OR Upper Parts Kit – Factory OEM Upgrade. The HK VP9 Optics Ready Upper Parts Kit is a genuine factory OEM assembly designed for precision, reliability, and optics compatibility. This complete set includes the barrel, recoil spring assemblies, striker components, extractor, firing pin safety, mounting screws, and slide parts – all engineered to HK’s exact standards. Built for smooth operation and long-term durability, it’s ideal for replacements, upgrades, or spare builds. Brand: Heckler & Koch (HK). Model: VP9 OR Upper Parts.