The Dead Air Shim Kit is a precision accessory designed to ensure the optimal timing of your muzzle device. It includes three shims of varying thicknesses, allowing for a custom-fit and the most accurate alignment possible. The packaging features a clear graphic that outlines the different shim thicknesses and their identifying characteristics. For proper installation, always start with the thickest shim on the barrel shoulder. This kit provides the precision needed to fine-tune your muzzle device for improved performance and reliability.