Fender super bullets are the ultimate string for fender trem users. nickel-plated steel makes these an excellent choice for rock and other styles of music where the guitar needs to cut through. Fender super bullets are one of the world's most-popular sets of strings and for good reason. The german-made end fits precisely into fender tremolo blocks, enhancing sustain and stability. That means they stay in tune better and they resonate more. By the way, the end isn't just for trem users;it also enhances sustain and stability on guitars with string-through-body type bridge designs.