AR-15 Thread Protector Compatibility : Designed to fit standard AR-15 barrels with 1/2"x28 threading. Dimensions : Features an outer diameter of 0.712", making it ideal for standard barrels (not suitable for Bull barrels). User-Friendly Design : The exterior is textured to ensure easy hand tightening, providing a secure and hassle-free installation. STATE RESTRICTION NOTICE This product may be regulated as an "assault weapon" feature or component (e.g., threaded barrel, muzzle device/compensator, or assembled upper) and may be restricted or prohibited in CA, CT, DC, HI, IL, MA, MD, NJ, NY, RI, VA, WA, and select municipalities. It is the buyer's responsibility to verify local, state, and federal laws before purchase. Orders that cannot ship to a restricted address will be canceled and refunded.