Hirschmann 4mm Series Safety Test Lead Sets A comprehensive range of safety test lead kits from Hirschmann Test and Measurement, these kits contain a combination of test leads, crocodile clips and grabber clips suitable for CAT II and CAT III (dependent upon the kit chosen) in black and red, part of the 4mm safety range. The test leads feature highly flexible silicon insulation and many hundreds of copper conductor strands that offer extremely long life and durability. Suitable for use with Oscilloscopes, multi-meters and other similar devices.