Yankee Hill Machine 10mm 9/16-24 Nielsen Pistons Silver. 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. Specifications for Yankee Hill Machine Nielsen Pistons: Manufacturer: Yankee Hill Machine Color: Silver Blade Finish: Stainless Steel Features of Yankee Hill Machine Nielsen Pistons: Weight: 1.40 oz Package Contents: Yankee Hill Machine Nielsen Pistons Yankee Hill Machine Yhm Nelson Piston .10mm 9/16-24