Rugged Suppressors 3-Lug Adapter 9mm Luger 5/8in-24 Tpi Threads Black. The No Go/Go Gauge provides confirmation that your suppressor is properly attached for a surprise free shooting experience. The 3 Lug Adapter is compatible and used in conjunction with OSS's 3 Lug Mount. This 3 Lug Adapter is made to 9mm HK spec and is not compatible with 45ACP. Specifications for Rugged Suppressors 9mm Luger 5/8-24 3-Lug Adapter: Manufacturer: Rugged Suppressors Color: Black Threads per Inch: 5/8x24 Package Contents: Rugged Suppressors 9mm Luger 5/8-24 3-Lug Adapter Rugged Suppressors OA006: 3-Lug Adapter 9mm Luger 5/8in-24 Tpi Threads Black