Unlock new possibilities for your Sig Sauer MCX Spear LT by seamlessly converting it to another caliber. With this upgrade, you'll be able to diversify your ammunition options, adapting your firearm to different shooting scenarios and preferences. Don't limit yourself to just one caliber, invest in the flexibility and adaptability that this conversion kit offers. Includes(1) Barrel, includes barrel extension(1) Gas piston assembly(1) Thread protector cap Note: This product does not include a muzzle device or magazine.