the spur hammered models are an earlier P220 with a folded steel slide, mostly with the heel magazine release, but many of them were released with "regular" magazine release buttons. i believe that SIG changed the P220 to the current hammer profile in the mid 1980's. if you do get a spur hammer p220, you will want to replace the springs even if they are in good condition, as SIG has uprated the springs on their handguns since the 1980's. the spur hammered guns are my favorite P220's, as the craftsmanship is fantastic.