The ATI Strikeforce Stock Drop Spacer Adapter Fits ATI's Ruger 10/22, Mini 14/Thirty and SKS Strikeforce Stocks Only. Drop Spacer Improves Stock Angle for Shooter to Align with Iron Sites. Strikeforce Stock Drop Spacer Lower the Vertical Angle of Your Stock and Lower Cheek Position 1/2”. Made from DuPont® Extreme Temperature Glass Reinforced Polymer. Manufactured in the USA. Limited Lifetime Warranty.