SIT Power Steel 9-42 Electric Guitar Strings Extra Light SIT Stainless Steel electric guitar strings have a stainless steel cover wrap over high tempered Swedish Steel core. If you want strings with a long life, take a look at Power Steels. Corrosion resistant stainless steel string last longer than any other string type, because the are immune to the detrimental affects of perspiration, finger oil, dirt, dust, and atmospheric humidity. Just wipe them down occasionally, to keep them clean, and they are almost indestructible. SIT's brightest sound. Great for all types of music, and they really do "Stay In Tune "(SIT). String Diameters: 0.009 .011 .016 .024 .032 .046 inch with bare 3rd sting. SIT stands for "Stay-In-Tune". The S. I. T. String Corp. is not a traditional guitar string company, but has broken the mold with their innovations and commitment to quality. They are a leading exporter of guitar strings, to a growing foreign market who wants quality US made guitar and bass strings. Their guitars strings are so reliable that the S. I. T. String Corp. guarantees them to Stay-In-Tune. In fact, they say "If nothing is causing slippage on your instrument, the S. I. T. String Corp. guarantees your strings to Stay-In-Tune and provide unsurpassed brilliance and bendability." They even provide string installation instructions on the back of the box. So, if you're a "tone freak", then you can rest assured your SIT's won't let you down. Tune up and enjoy.