A Heiser model 457 holster for a 4" Smith & Wesson Combat Magnum .357 revolver-it will also fit the .38 Spl. Combat Masterpiece revolver.The target rear sight rides outside the holster.First cataloged before WW II,this was Heiser's version of the Threepersons type holster.The number 36 catalog (late 1930's) says "Following holsters are made of heavy oak-tanned California skirting leather,closed end,unlined,waxed thread sewed,belt loop on back,there is a welt down the side...welt permits a snug fit. A small hole is left in bottom to permit any dirt to sift out.Gun sets high exposing trigger guard & trigger.This holster was designed for the F.B.I. of Washington,D.C. who require holster for fast draw."Please request a photo of this holster with a pre-model 19 Combat Magnum revolver in it.Excellent overall condition-stiff heavy leather construction,all stitching is tight,will fit up to a 2" wide belt,forward cant,some signs of use & some light crazing on the front,stamped with the oval Heiser logo & the model number 457.Please ask any questions you'd like.