I believe based on the serial prefix this is for an HK P30 in. For these barrels I have simply patched the bores and quickly wiped the exterior. I do not know if they have been custom fitted to a gun or modified. Please pay attention to locking lugs and other features to cross reference with the gun you want this for and ask all questions you have before purchasing. I list my ads high so that you can submit an offer of what you feel is fair.