45-135 Black Label (Medium gauge) Medium Low B Bass String pack from Warwick. This Warwick Black Label (Medium gauge) Medium Low B string pack 45-135 is for 5-string basses. The set consists of .045″ .065″ .085″ .105″ .135″ sizes. These are handmade stainless steel roundwound strings. They have very precise intonation with a full brilliant tone. These are what are strung on to Warwick basses. These Warwick bass strings boast carefully chosen materials. The adjustment of core and winding wire give an even tension well balanced overtone responses as well as an even magnetic response when being picked up.