Welcome to our store! 1. Application: The heavy-duty M9x0.75 to 1/2-28 adapter is designed as a replacement for Sig Sauer 1911 22, GSG 1911 22, 5PK 22, and some others that have M9x0.75 threads. 2. Flat Ridge Design: The M9x0.75 to 1/2-28 threaded adapter comes with flat ridges for easy assembly and removal with a wrench (not included), improving operational efficiency. 3. With Thread Protector: The M9x0.75 to 1/2-28 adapter is equipped with a 1/2-28 thread protector to protect the 1/2-28 thread when used without accessories or for storage. 4. Knurled Design: The 1/2-28 thread protector is professionally designed with a fine diamond ring, giving it an attractive and elegant look, and providing increased friction to prevent slippage. 5. Durable Construction: The M9x0.75 to 1/2-28 adapter with thread protector is constructed of premium high-carbon steel with a black oxide finish, making it resistant to rust and highly durable. Item Type: M9x0.75 to 1/2-28 Adapter Material: High Carbon Steel Pipe End Thread: M9 (9 mm) x 0.75 mm Adapter Thread Outer Diameter: 1/2-28 Fully Screw-On Cap Length: Approx. 1.25 in / 3.2 cm Maximum Diameter (with protective cap installed): Approx. 1.59 cm / 5/8 in Compatible with: Sig Sauer 1911 22, GSG 1911 22, 5PK 22, and others with M9x0.75 threads. Includes one M9x0.75 to 1/2-28 adapter. Our customers are our priority. If you encounter any problems with your product after receiving it, such as damage or an incorrect quantity, please contact us immediately. We strive to provide you with the best after-sales service.