I have designed new string ferrules for Tele style guitars. The ball-end of the guitar string fits nice and snug and almost  flush with the end of the ferrule. This makes for much better string contact with the body allowing more vibration through the guitar, adding sustain, brilliance and improving overall tone. You can choose from titanium, brass, cold rolled steel, and aluminum sets or you can mix and match to achieve your own personal sound. For example; aluminum for the low E/A strings, cold rolled steel for the D/G strings, and brass for the high B/E strings. The brass removes harsh overtones from the high strings and adds harmonic richness. The titanium is very well balanced and is a  little brighter than brass,  it also removes harsh overtones from the high strings and adds harmonic richness. Titanium works very good on all six strings. The aluminum tightens up the low end giving more punch and a touch more volume. The "Retro-Rockets" are direct replacements for vintage-style and American Standard Tele's fitting in a 5/16" hole with a 3/8" countersink.