If you use a Floyd Rose type, tremolo system and are looking for exceptional, hook end strings that are easy to install, then these strings are for you. Our SIT Super Hook strings are less prone to breakage and are indeed guaranteed to "Stay In Tune." Since 1973, the SIT Strings Company has been dedicated to producing the best quality strings possible. They stay on the cutting edge of string technology, with a strong focus on quality control. The SIT Super Hooks are their power wound strings, which feature nickel-plated wrapping over high tempered steel, hexagonal cores.