When looking up part numbers for BAS Series Resistors from Isabellenhuette, you may see the “ABU” suffix at the end of the orderable part numbers. One example would be BAS-M-R0001-ABU-5.0 .
Isabellenhuette has confirmed that BAS-M-R0001-ABU-5.0 is a slightly customized version.
“A” = Automotive Version
“B” = Custom Length
“U” = Untinned