The White Label Armory Castle Nut is designed to provide a secure and vibration-resistant lock for the receiver extension on your AR-platform lower receiver. Ideal for finishing a new build or replacing a staked factory nut, this component ensures the buffer tube remains firmly indexed to the receiver under the heavy stresses of recoil. Manufactured from high-strength steel and built to meet standard Mil-Spec dimensions, the castle nut is precision-machined with deep notches for a reliable wrench interface and consistent torque application. Utilizing a high-quality castle nut helps maintain the structural alignment of your stock assembly, allows for proper staking to prevent unintended loosening, and contributes to the overall mechanical integrity and long-term durability of your firearm.