I have three new in the sealed box Sig CALXMCX9B300TAP MCX Virtus 9" 300BLK caliber conversion kits for $750 each shipped. The photos are of a kit that I have opened but the ones I'm selling are unopened and still sealed in the box from Sig. Each kit includes a complete barrel with valve and piston, tapered lug bolt, 25deg shoulder adapter for using certain muzzle devices, and the T27 wrench to change the barrel. This kit can be used in a "Legacy" or Virtus series MCX but if you want to use it in a Rattler series MCX you will need to obtain a Virtus op rod for your Rattler carrier assembly. Please post a reply, send an email, and send me an IM so I know who to respond to. Free insured shipping to the 48 contiguous United States. If you are in Alaska or Hawiaii contact me first to get a quote for additional shipping. I will not ship outside of the 50 United States. Payment by USPS, Western Union, bank, credit union, retail chain store, or other verifiable money order or zelle. These barrels are only for use in legally configured pistols or registered short barreled rifles. It is your responsibility to ensure that you are not in violation of any local, state, or federal ordnance or law in your use or possession of a centerfire barrel less than 16" in length.