String Saver is made from a proprietary material which is precision engineered under high pressure and heat. It is impregnated with PTFE throughout so it will reduce the friction between the saddles and the strings.  It is specifically formulated to deliver the right frequencies with the optimum transfer rate to the top of your guitar every time.  Because of the way String Saver is made, it is a consistent material that is rich in tone and harmonic content.