Professional Leaded Resistors The Vishay / BC Components Professional Leaded Resistors are general purpose resistors with small outlines, low noise, and Lead-free solder contacts. The Vishay / BC Components Professional Leaded Resistors are composed of pure tin plating to provide compatibility with lead-free and lead-containing soldering processes. The Professional Leaded Resistors are also compatible with 'Restriction of the use of Hazardous Substances' (RoHS) directive 2002/95/EC (issue 2004).