Check the listing for details. 12ga to 45 ACP Shotgun Adapter - Chamber Reducer 6" Long. Condition: New. Listed at 75.47 USD. 12ga to 45 ACP Shotgun AdaptersLength: 6" 45 ACP Shotgun Adapters Allow a 12 Gauge Break Action Shotgun to use 45 ACP ammo. For 3″ as well as 2.75″ ChambersCompatible with Break Action single as well as double barrel shotgun.Comes with multiple O-ring configurations. As a result, easily achieving a good fit for 12 gauge shotguns.Finger Grooves for easy extraction of spent casings.Black Oxide coating as a result provides notably better corrosion protection (for maximum corrosion protection keep a thin coat of oil on the insert)Rifle dimensions: .451″/.445″ with 6 lands and .145″ wide with a 1:14 twist rate Made in the USA!! If you're not happy with the product for any reason send it back within 30 days and I will refund your money.