Product Description The Rugged Suppressors 3-Lug Adapter (OA004) is a durable, precisely manufactured barrel adapter designed to enable fast attach/detach use of a 3-lug suppressor mounting system on compatible 9mm hosts. Featuring Rugged&';s Go/No Go gauge markings, it helps confirm proper suppressor attachment for added confidence on the range. This adapter is made to 9mm H&K specifications and is intended for use with the Rugged Obsidian9 3 Lug Mount, using M13.5x1 left-hand muzzle threads. Product Highlights 3-lug barrel adapter for quick twist-lock suppressor mounting on compatible 9mm platforms M13.5x1 left-hand (LH) thread pattern for hosts with metric LH muzzle threads Go/No Go markings help verify correct suppressor attachment Built to 9mm H&K specifications for compatibility with the Obsidian9 3 Lug Mount system Durable construction with precise manufacturing for long-term reliability Specs Brand: Rugged Suppressors Manufacturer Part Number: OA004 UPC: 859383006716 Product Type: 3-Lug Adapter / Suppressor Mounting Accessory Thread Pattern: M13.5x1 LH Compatibility: Rugged Obsidian9 3 Lug Mount (used in conjunction) Caliber Compatibility: 9mm (not compatible with .45 ACP) Color/Finish: Black Disclaimer: We strive to provide accurate and up-to-date product descriptions, specifications, and images; however, errors or omissions may occasionally occur. We are not responsible for any inaccuracies or discrepancies in the content provided. If you notice anything incorrect or unclear, please contact us so we can correct it. When in doubt, we recommend verifying details directly with the product&';s manufacturer.