A friend of mine has a gen one Glock 17 and he bought it with all the mods at a gun show. It has an all metal recoil spring that is fixed to the guide rod and looks just like the stock recoil spring but it is all metal. It also makes a sound when you work the slide back that I love. I have searched high and low on the net and can not find one. Yes I've seen the spring co and the wolf two peice guide rod sets, but this is a one peice. Does anyone know who makes these? Thanks...