Ernie Ball 2736EB Cobalt Bass 5-Str Slinky Cobalt Slinky Electric Bass Strings 5-String Set 045 - 130These Cobalt Slinky Bass Strings from Ernie Ball are intended for use with 5 string electric basses and feature a proprietary iron cobalt alloy wrap wire over a tin plated high carbon steel hex core wire. This proprietary cobalt alloy provides a stronger magnetic relationship between your strings and your pickups when compared to other alloys used for making strings. As such, they help facilitate an increased output level with a wider dynamic range