Yankee Hill Nielsen 9mm Stainless Stainless Steel. They are constructed from heat treated 17-4 stainless steel for maximum durability and corrosion resistance. They feature 10 adjustment points to zero any impact shift. Available in a variety of thread patterns to fit most firearms. Weight: 1.40 oz. Not compatible with Sidewinder suppressors Specifications for Yankee Hill 206028 Nielsen 2060-28 9mm Stainless Stainless Steel: Manufacturer: Yankee Hill Machine Fabric/Material: Stainless Steel Finish: Stainless Gun Type: Universal Yankee Hill 206028 Nielsen 2060-28 9mm Stainless Stainless Steel