.22 LR. 5" barrel length. SN: U1592. Polished blued metal finish overall with polished extractor and floating chamber, and mounting matted front ramp and adjustable target rear sights. Conversion unit for Colt Model 1911 pattern pistols capable of permitting them to fire .22 Long Rifle ammunition for training purposes. Left slide struck with the two line legend COLT'S PT. F.A. MFG. CO. HARTFORD, CT. U.S.A./PATENT NUMBERS 2,090,656 2,090,657 followed by the {Rampant Colt} logo forward of the cocking serrations. Right slide marked COLT SERVICE/MODEL/CONVERSION followed by ACE within diamond and .22 LONG/RIFLE/UNIT .22-45. Item comes in matching cardboard box with black paper liner. Item retains the COLT label to the lid with an inventory list to the interior lid. Included in the box are the manual, slide, barrel, floating chamber, ejector, bushing, magazine, recoil spring, recoil spring guide, recoil spring plug, and the slide stop. Magazine floorplate reads COLT/22 ACE L.R./SERVICE MODEL. Item additionally comes with Colt Collectors Association historians letter affirming that it was shipped to the United States Marine Corps on December 17, 1942.