Manufactured between 1986 and 1988. This is an example of a U.S. Customs Service Model 686 revolver. These revolvers are set apart from the normal 686 by their special matte finish and "CS-1" marking on the inside of the frame. This example features the rare 3 inch barrel with pinned serrated blade front and adjustable rear sights, which according to the included copy of a Smith & Wesson factory letter for a different U.S. Customs S&W Model 686 revolver, only saw 3281 units produced. Many of these revolvers were sold through commercial means once Customs retired them. The CS-1 Model 686 revolvers were built to the exacting specification of the U.S. Customs armorers in Glynco, Georgia to create a supremely accurate and dependable service revolver which would stand up to the wear and tear of Customs duty. The specification of these desirable revolvers was altered slightly when Smith & Wesson told Customs that the frame to forcing cone gap was too narrow and the revolver would not function properly. The Model 686 revolver served U.S. Customs for only a short period of time being phased out during 1988-89 in favor of more modern semi-automatic pistols, causing only a small number of revolvers to be manufactured. FTF ONLY.