Enhance your shooting experience with the Rugged Suppressors 3 Lug Adapter expertly engineered for 9mm HK specifications. This innovative adapter features the exclusive GoNo Go Gauge ensuring your suppressor is securely attached for a flawless performance every time. Designed to work seamlessly with OSS's 3 Lug Mount this adapter offers a reliable solution for firearm enthusiasts. With a 1/2"-36 tpi thread pattern it stands out by providing compatibility tailored specifically for 9mm ensuring precision and ease of use. Please note this model is not suitable for 45ACP firearms.