Mueller bu 75k black gold plated mini kelvin crocodile clip 10a mueller bu 75k p a kelvin or kelvinized clip has jaws teeth or contacts that are electrically isolated from each other in practice one jaw will carry the current and the other jaw will be used to sense the voltage when used properly kelvin clips provide a much more accurate reading at low voltages compared to a single wire clip p p the mueller bu 75k is the most popular miniature kelvin clip on the market its gold plat